diff --git a/lib/deprecatedlib.php b/lib/deprecatedlib.php
index 1b3511f70aa..c28996f6587 100644
--- a/lib/deprecatedlib.php
+++ b/lib/deprecatedlib.php
@@ -748,57 +748,12 @@ function print_side_block() {
 }
 
 /**
- * Prints a basic textarea field.
- *
- * This was 'deprecated' in 2.0, but not properly (there was no alternative) so the
- * debugging message was commented out.
- *
  * @deprecated since Moodle 3.6
- *
- * When using this function, you should
- *
- * @global object
- * @param bool $unused No longer used.
- * @param int $rows Number of rows to display  (minimum of 10 when $height is non-null)
- * @param int $cols Number of columns to display (minimum of 65 when $width is non-null)
- * @param null $width (Deprecated) Width of the element; if a value is passed, the minimum value for $cols will be 65. Value is otherwise ignored.
- * @param null $height (Deprecated) Height of the element; if a value is passe, the minimum value for $rows will be 10. Value is otherwise ignored.
- * @param string $name Name to use for the textarea element.
- * @param string $value Initial content to display in the textarea.
- * @param int $obsolete deprecated
- * @param bool $return If false, will output string. If true, will return string value.
- * @param string $id CSS ID to add to the textarea element.
- * @return string|void depending on the value of $return
  */
-function print_textarea($unused, $rows, $cols, $width, $height, $name, $value='', $obsolete=0, $return=false, $id='') {
-    /// $width and height are legacy fields and no longer used as pixels like they used to be.
-    /// However, you can set them to zero to override the mincols and minrows values below.
-
-    // Disabling because there is not yet a viable $OUTPUT option for cases when mforms can't be used
-    debugging('print_textarea() is deprecated. Please use $OUTPUT->print_textarea() instead.', DEBUG_DEVELOPER);
-
-    global $OUTPUT;
-
-    $mincols = 65;
-    $minrows = 10;
-
-    if ($id === '') {
-        $id = 'edit-'.$name;
-    }
-
-    if ($height && ($rows < $minrows)) {
-        $rows = $minrows;
-    }
-    if ($width && ($cols < $mincols)) {
-        $cols = $mincols;
-    }
-
-    $textarea = $OUTPUT->print_textarea($name, $id, $value, $rows, $cols);
-    if ($return) {
-        return $textarea;
-    }
-
-    echo $textarea;
+function print_textarea() {
+    throw new coding_exception(
+        'print_textarea() has been removed. Please use $OUTPUT->print_textarea() instead.'
+    );
 }
 
 /**
@@ -2668,542 +2623,133 @@ function message_delete_message() {
 }
 
 /**
- * Get all of the allowed types for all of the courses and groups
- * the logged in user belongs to.
- *
- * The returned array will optionally have 5 keys:
- *      'user' : true if the logged in user can create user events
- *      'site' : true if the logged in user can create site events
- *      'category' : array of course categories that the user can create events for
- *      'course' : array of courses that the user can create events for
- *      'group': array of groups that the user can create events for
- *      'groupcourses' : array of courses that the groups belong to (can
- *                       be different from the list in 'course'.
  * @deprecated since 3.6
- * @return array The array of allowed types.
  */
 function calendar_get_all_allowed_types() {
-    debugging('calendar_get_all_allowed_types() is deprecated. Please use calendar_get_allowed_types() instead.',
-        DEBUG_DEVELOPER);
+    throw new coding_exception(
+        'calendar_get_all_allowed_types() has been removed. Please use calendar_get_allowed_types() instead.'
+    );
 
-    global $CFG, $USER, $DB;
-
-    require_once($CFG->libdir . '/enrollib.php');
-
-    $types = [];
-
-    $allowed = new stdClass();
-
-    calendar_get_allowed_types($allowed);
-
-    if ($allowed->user) {
-        $types['user'] = true;
-    }
-
-    if ($allowed->site) {
-        $types['site'] = true;
-    }
-
-    if (core_course_category::has_manage_capability_on_any()) {
-        $types['category'] = core_course_category::make_categories_list('moodle/category:manage');
-    }
-
-    // This function warms the context cache for the course so the calls
-    // to load the course context in calendar_get_allowed_types don't result
-    // in additional DB queries.
-    $courses = calendar_get_default_courses(null, 'id, groupmode, groupmodeforce', true);
-
-    // We want to pre-fetch all of the groups for each course in a single
-    // query to avoid calendar_get_allowed_types from hitting the DB for
-    // each separate course.
-    $groups = groups_get_all_groups_for_courses($courses);
-
-    foreach ($courses as $course) {
-        $coursegroups = isset($groups[$course->id]) ? $groups[$course->id] : null;
-        calendar_get_allowed_types($allowed, $course, $coursegroups);
-
-        if (!empty($allowed->courses)) {
-            $types['course'][$course->id] = $course;
-        }
-
-        if (!empty($allowed->groups)) {
-            $types['groupcourses'][$course->id] = $course;
-
-            if (!isset($types['group'])) {
-                $types['group'] = array_values($allowed->groups);
-            } else {
-                $types['group'] = array_merge($types['group'], array_values($allowed->groups));
-            }
-        }
-    }
-
-    return $types;
 }
 
 /**
- * Gets array of all groups in a set of course.
- *
- * @category group
- * @param array $courses Array of course objects or course ids.
- * @return array Array of groups indexed by course id.
+ * @deprecated since Moodle 3.6.
  */
-function groups_get_all_groups_for_courses($courses) {
-    global $DB;
-
-    if (empty($courses)) {
-        return [];
-    }
-
-    $groups = [];
-    $courseids = [];
-
-    foreach ($courses as $course) {
-        $courseid = is_object($course) ? $course->id : $course;
-        $groups[$courseid] = [];
-        $courseids[] = $courseid;
-    }
-
-    $groupfields = [
-        'g.id as gid',
-        'g.courseid',
-        'g.idnumber',
-        'g.name',
-        'g.description',
-        'g.descriptionformat',
-        'g.enrolmentkey',
-        'g.picture',
-        'g.hidepicture',
-        'g.timecreated',
-        'g.timemodified'
-    ];
-
-    $groupsmembersfields = [
-        'gm.id as gmid',
-        'gm.groupid',
-        'gm.userid',
-        'gm.timeadded',
-        'gm.component',
-        'gm.itemid'
-    ];
-
-    $concatidsql = $DB->sql_concat_join("'-'", ['g.id', 'COALESCE(gm.id, 0)']) . ' AS uniqid';
-    list($courseidsql, $params) = $DB->get_in_or_equal($courseids);
-    $groupfieldssql = implode(',', $groupfields);
-    $groupmembersfieldssql = implode(',', $groupsmembersfields);
-    $sql = "SELECT {$concatidsql}, {$groupfieldssql}, {$groupmembersfieldssql}
-              FROM {groups} g
-         LEFT JOIN {groups_members} gm
-                ON gm.groupid = g.id
-             WHERE g.courseid {$courseidsql}";
-
-    $results = $DB->get_records_sql($sql, $params);
-
-    // The results will come back as a flat dataset thanks to the left
-    // join so we will need to do some post processing to blow it out
-    // into a more usable data structure.
-    //
-    // This loop will extract the distinct groups from the result set
-    // and add it's list of members to the object as a property called
-    // 'members'. Then each group will be added to the result set indexed
-    // by it's course id.
-    //
-    // The resulting data structure for $groups should be:
-    // $groups = [
-    //      '1' = [
-    //          '1' => (object) [
-    //              'id' => 1,
-    //              <rest of group properties>
-    //              'members' => [
-    //                  '1' => (object) [
-    //                      <group member properties>
-    //                  ],
-    //                  '2' => (object) [
-    //                      <group member properties>
-    //                  ]
-    //              ]
-    //          ],
-    //          '2' => (object) [
-    //              'id' => 2,
-    //              <rest of group properties>
-    //              'members' => [
-    //                  '1' => (object) [
-    //                      <group member properties>
-    //                  ],
-    //                  '3' => (object) [
-    //                      <group member properties>
-    //                  ]
-    //              ]
-    //          ]
-    //      ]
-    // ]
-    //
-    foreach ($results as $key => $result) {
-        $groupid = $result->gid;
-        $courseid = $result->courseid;
-        $coursegroups = $groups[$courseid];
-        $groupsmembersid = $result->gmid;
-        $reducefunc = function($carry, $field) use ($result) {
-            // Iterate over the groups properties and pull
-            // them out into a separate object.
-            list($prefix, $field) = explode('.', $field);
-
-            if (property_exists($result, $field)) {
-                $carry[$field] = $result->{$field};
-            }
-
-            return $carry;
-        };
-
-        if (isset($coursegroups[$groupid])) {
-            $group = $coursegroups[$groupid];
-        } else {
-            $initial = [
-                'id' => $groupid,
-                'members' => []
-            ];
-            $group = (object) array_reduce(
-                $groupfields,
-                $reducefunc,
-                $initial
-            );
-        }
-
-        if (!empty($groupsmembersid)) {
-            $initial = ['id' => $groupsmembersid];
-            $groupsmembers = (object) array_reduce(
-                $groupsmembersfields,
-                $reducefunc,
-                $initial
-            );
-
-            $group->members[$groupsmembers->userid] = $groupsmembers;
-        }
-
-        $coursegroups[$groupid] = $group;
-        $groups[$courseid] = $coursegroups;
-    }
-
-    return $groups;
+function groups_get_all_groups_for_courses() {
+    throw new coding_exception(
+        'groups_get_all_groups_for_courses() has been removed and can not be used anymore.'
+    );
 }
 
 /**
- * Gets the capabilities that have been cached in the database for this
- * component.
  * @deprecated since Moodle 3.6. Please use the Events 2 API.
- * @todo final deprecation. To be removed in Moodle 4.0
- *
- * @access protected To be used from eventslib only
- *
- * @param string $component examples: 'moodle', 'mod_forum', 'block_quiz_results'
- * @return array of events
  */
-function events_get_cached($component) {
-    global $DB;
-
-    debugging('Events API using $handlers array has been deprecated in favour of Events 2 API, please use it instead.',
-            DEBUG_DEVELOPER);
-
-    $cachedhandlers = array();
-
-    if ($storedhandlers = $DB->get_records('events_handlers', array('component'=>$component))) {
-        foreach ($storedhandlers as $handler) {
-            $cachedhandlers[$handler->eventname] = array (
-                'id'              => $handler->id,
-                'handlerfile'     => $handler->handlerfile,
-                'handlerfunction' => $handler->handlerfunction,
-                'schedule'        => $handler->schedule,
-                'internal'        => $handler->internal);
-        }
-    }
-
-    return $cachedhandlers;
+function events_get_cached() {
+    throw new coding_exception(
+        'Events API using $handlers array has been removed in favour of Events 2 API, please use it instead.'
+    );
 }
 
 /**
- * Remove all event handlers and queued events
  * @deprecated since Moodle 3.6. Please use the Events 2 API.
- * @todo final deprecation. To be removed in Moodle 4.0
- *
- * @category event
- * @param string $component examples: 'moodle', 'mod_forum', 'block_quiz_results'
  */
-function events_uninstall($component) {
-    debugging('Events API using $handlers array has been deprecated in favour of Events 2 API, please use it instead.',
-            DEBUG_DEVELOPER);
-    $cachedhandlers = events_get_cached($component);
-    events_cleanup($component, $cachedhandlers);
-
-    events_get_handlers('reset');
+function events_uninstall() {
+    throw new coding_exception(
+        'Events API using $handlers array has been removed in favour of Events 2 API, please use it instead.'
+    );
 }
 
 /**
- * Deletes cached events that are no longer needed by the component.
  * @deprecated since Moodle 3.6. Please use the Events 2 API.
- * @todo final deprecation. To be removed in Moodle 4.0
- *
- * @access protected To be used from eventslib only
- *
- * @param string $component examples: 'moodle', 'mod_forum', 'block_quiz_results'
- * @param array $cachedhandlers array of the cached events definitions that will be
- * @return int number of unused handlers that have been removed
  */
-function events_cleanup($component, $cachedhandlers) {
-    global $DB;
-    debugging('Events API using $handlers array has been deprecated in favour of Events 2 API, please use it instead.',
-            DEBUG_DEVELOPER);
-    $deletecount = 0;
-    foreach ($cachedhandlers as $eventname => $cachedhandler) {
-        if ($qhandlers = $DB->get_records('events_queue_handlers', array('handlerid'=>$cachedhandler['id']))) {
-            //debugging("Removing pending events from queue before deleting of event handler: $component - $eventname");
-            foreach ($qhandlers as $qhandler) {
-                events_dequeue($qhandler);
-            }
-        }
-        $DB->delete_records('events_handlers', array('eventname'=>$eventname, 'component'=>$component));
-        $deletecount++;
-    }
-
-    return $deletecount;
+function events_cleanup() {
+    throw new coding_exception(
+        'Events API using $handlers array has been removed in favour of Events 2 API, please use it instead.'
+    );
 }
 
 /**
- * Removes this queued handler from the events_queued_handler table
- *
- * Removes events_queue record from events_queue if no more references to this event object exists
  * @deprecated since Moodle 3.6. Please use the Events 2 API.
- * @todo final deprecation. To be removed in Moodle 4.0
- *
- * @access protected To be used from eventslib only
- *
- * @param stdClass $qhandler A row from the events_queued_handler table
  */
-function events_dequeue($qhandler) {
-    global $DB;
-    debugging('Events API using $handlers array has been deprecated in favour of Events 2 API, please use it instead.',
-            DEBUG_DEVELOPER);
-    // first delete the queue handler
-    $DB->delete_records('events_queue_handlers', array('id'=>$qhandler->id));
-
-    // if no more queued handler is pointing to the same event - delete the event too
-    if (!$DB->record_exists('events_queue_handlers', array('queuedeventid'=>$qhandler->queuedeventid))) {
-        $DB->delete_records('events_queue', array('id'=>$qhandler->queuedeventid));
-    }
+function events_dequeue() {
+    throw new coding_exception(
+        'Events API using $handlers array has been removed in favour of Events 2 API, please use it instead.'
+    );
 }
 
 /**
- * Returns handlers for given event. Uses caching for better perf.
  * @deprecated since Moodle 3.6. Please use the Events 2 API.
- * @todo final deprecation. To be removed in Moodle 4.0
- *
- * @access protected To be used from eventslib only
- *
- * @staticvar array $handlers
- * @param string $eventname name of event or 'reset'
- * @return array|false array of handlers or false otherwise
  */
-function events_get_handlers($eventname) {
-    global $DB;
-    static $handlers = array();
-    debugging('Events API using $handlers array has been deprecated in favour of Events 2 API, please use it instead.',
-            DEBUG_DEVELOPER);
-
-    if ($eventname === 'reset') {
-        $handlers = array();
-        return false;
-    }
-
-    if (!array_key_exists($eventname, $handlers)) {
-        $handlers[$eventname] = $DB->get_records('events_handlers', array('eventname'=>$eventname));
-    }
-
-    return $handlers[$eventname];
+function events_get_handlers() {
+    throw new coding_exception(
+        'Events API using $handlers array has been removed in favour of Events 2 API, please use it instead.'
+    );
 }
 
 /**
- * This function finds the roles assigned directly to this context only
- * i.e. no roles in parent contexts
- *
  * @deprecated since Moodle 3.6. Please use the get_roles_used_in_context().
- * @todo final deprecation. To be removed in Moodle 4.0
- * @param context $context
- * @return array
  */
-function get_roles_on_exact_context(context $context) {
-    debugging('get_roles_on_exact_context() is deprecated, please use get_roles_used_in_context() instead.',
-        DEBUG_DEVELOPER);
-
-    return get_roles_used_in_context($context, false);
+function get_roles_on_exact_context() {
+    throw new coding_exception(
+        'get_roles_on_exact_context() has been removed, please use get_roles_used_in_context() instead.'
+    );
 }
 
 /**
- * Find out which roles has assignment on this context
- *
  * @deprecated since Moodle 3.6. Please use the get_roles_used_in_context().
- * @todo final deprecation. To be removed in Moodle 4.0
- * @param context $context
- * @return array
  */
-function get_roles_with_assignment_on_context(context $context) {
-    debugging('get_roles_with_assignment_on_context() is deprecated, please use get_roles_used_in_context() instead.',
-        DEBUG_DEVELOPER);
-
-    return get_roles_used_in_context($context, false);
+function get_roles_with_assignment_on_context() {
+    throw new coding_exception(
+        'get_roles_with_assignment_on_context() has been removed, please use get_roles_used_in_context() instead.'
+    );
 }
 
 /**
- * Add the selected user as a contact for the current user
- *
  * @deprecated since Moodle 3.6
- * @param int $contactid the ID of the user to add as a contact
- * @param int $blocked 1 if you wish to block the contact
- * @param int $userid the user ID of the user we want to add the contact for, defaults to current user if not specified.
- * @return bool/int false if the $contactid isnt a valid user id. True if no changes made.
- *                  Otherwise returns the result of update_record() or insert_record()
  */
-function message_add_contact($contactid, $blocked = 0, $userid = 0) {
-    debugging('message_add_contact() is deprecated. Please use \core_message\api::create_contact_request() instead. ' .
+function message_add_contact() {
+    throw new coding_exception(
+        'message_add_contact() has been removed. Please use \core_message\api::create_contact_request() instead. ' .
         'If you wish to block or unblock a user please use \core_message\api::is_blocked() and ' .
-        '\core_message\api::block_user() or \core_message\api::unblock_user() respectively.', DEBUG_DEVELOPER);
-
-    global $USER, $DB;
-
-    if (!$DB->record_exists('user', array('id' => $contactid))) {
-        return false;
-    }
-
-    if (empty($userid)) {
-        $userid = $USER->id;
-    }
-
-    // Check if a record already exists as we may be changing blocking status.
-    if (\core_message\api::is_contact($userid, $contactid)) {
-        $isblocked = \core_message\api::is_blocked($userid, $contactid);
-        // Check if blocking status has been changed.
-        if ($isblocked != $blocked) {
-            if ($blocked == 1) {
-                if (!$isblocked) {
-                    \core_message\api::block_user($userid, $contactid);
-                }
-            } else {
-                \core_message\api::unblock_user($userid, $contactid);
-            }
-
-            return true;
-        } else {
-            // No change to blocking status.
-            return true;
-        }
-    } else {
-        if ($blocked == 1) {
-            if (!\core_message\api::is_blocked($userid, $contactid)) {
-                \core_message\api::block_user($userid, $contactid);
-            }
-        } else {
-            \core_message\api::unblock_user($userid, $contactid);
-            if (!\core_message\api::does_contact_request_exist($userid, $contactid)) {
-                \core_message\api::create_contact_request($userid, $contactid);
-            }
-        }
-
-        return true;
-    }
+        '\core_message\api::block_user() or \core_message\api::unblock_user() respectively.'
+    );
 }
 
 /**
- * Remove a contact.
- *
  * @deprecated since Moodle 3.6
- * @param int $contactid the user ID of the contact to remove
- * @param int $userid the user ID of the user we want to remove the contacts for, defaults to current user if not specified.
- * @return bool returns the result of delete_records()
  */
-function message_remove_contact($contactid, $userid = 0) {
-    debugging('message_remove_contact() is deprecated. Please use \core_message\api::remove_contact() instead.',
-        DEBUG_DEVELOPER);
-
-    global $USER;
-
-    if (empty($userid)) {
-        $userid = $USER->id;
-    }
-
-    \core_message\api::remove_contact($userid, $contactid);
-
-    return true;
+function message_remove_contact() {
+    throw new coding_exception(
+        'message_remove_contact() has been removed. Please use \core_message\api::remove_contact() instead.'
+    );
 }
 
 /**
- * Unblock a contact.
- *
  * @deprecated since Moodle 3.6
- * @param int $contactid the user ID of the contact to unblock
- * @param int $userid the user ID of the user we want to unblock the contact for, defaults to current user
- *  if not specified.
- * @return bool returns the result of delete_records()
  */
-function message_unblock_contact($contactid, $userid = 0) {
-    debugging('message_unblock_contact() is deprecated. Please use \core_message\api::unblock_user() instead.',
-        DEBUG_DEVELOPER);
-
-    global $DB, $USER;
-
-    if (!$DB->record_exists('user', array('id' => $contactid))) {
-        return false;
-    }
-
-    if (empty($userid)) {
-        $userid = $USER->id;
-    }
-
-    \core_message\api::unblock_user($userid, $contactid);
-
-    return true;
+function message_unblock_contact() {
+    throw new coding_exception(
+        'message_unblock_contact() has been removed. Please use \core_message\api::unblock_user() instead.'
+    );
 }
 
 /**
- * Block a user.
- *
  * @deprecated since Moodle 3.6
- * @param int $contactid the user ID of the user to block
- * @param int $userid the user ID of the user we want to unblock the contact for, defaults to current user
- *  if not specified.
- * @return bool
  */
-function message_block_contact($contactid, $userid = 0) {
-    debugging('message_block_contact() is deprecated. Please use \core_message\api::is_blocked() and ' .
-        '\core_message\api::block_user() instead.', DEBUG_DEVELOPER);
-
-    global $DB, $USER;
-
-    if (!$DB->record_exists('user', array('id' => $contactid))) {
-        return false;
-    }
-
-    if (empty($userid)) {
-        $userid = $USER->id;
-    }
-
-    if (!\core_message\api::is_blocked($userid, $contactid)) {
-        \core_message\api::block_user($userid, $contactid);
-    }
-
-    return true;
+function message_block_contact() {
+    throw new coding_exception(
+        'message_block_contact() has been removed. Please use \core_message\api::is_blocked() and ' .
+        '\core_message\api::block_user() instead.'
+    );
 }
 
 /**
- * Load a user's contact record
- *
  * @deprecated since Moodle 3.6
- * @param int $contactid the user ID of the user whose contact record you want
- * @return array message contacts
  */
-function message_get_contact($contactid) {
-    debugging('message_get_contact() is deprecated. Please use \core_message\api::get_contact() instead.',
-        DEBUG_DEVELOPER);
-
-    global $USER;
-
-    return \core_message\api::get_contact($USER->id, $contactid);
+function message_get_contact() {
+    throw new coding_exception(
+        'message_get_contact() has been removed. Please use \core_message\api::get_contact() instead.'
+    );
 }
 
 /**
diff --git a/lib/tests/event_test.php b/lib/tests/event_test.php
index 8c094f33159..9e71470e1dc 100644
--- a/lib/tests/event_test.php
+++ b/lib/tests/event_test.php
@@ -596,7 +596,7 @@ class core_event_testcase extends advanced_testcase {
         events_update_definition('unittest');
 
         $DB->delete_records_select('events_handlers', "component <> 'unittest'");
-        events_get_handlers('reset');
+
         $this->assertDebuggingCalled(self::DEBUGGING_MSG, DEBUG_DEVELOPER);
         $this->assertEquals(3, $DB->count_records('events_handlers'));
         set_config('loglifetime', 60*60*24*5);
diff --git a/lib/upgrade.txt b/lib/upgrade.txt
index d1e8450ca79..8ddc5de4864 100644
--- a/lib/upgrade.txt
+++ b/lib/upgrade.txt
@@ -9,6 +9,22 @@ information provided here is intended especially for developers.
 * The `$CFG->behat_retart_browser_after` configuration setting has been removed.
   The browser session is now restarted between all tests.
 * add_to_log() has been through final deprecation, please rewrite your code to the new events API.
+* The following functions have been finally deprecated and can not be used anymore:
+  - print_textarea
+  - calendar_get_all_allowed_types
+  - groups_get_all_groups_for_courses
+  - events_get_cached
+  - events_uninstall
+  - events_cleanup
+  - events_dequeue
+  - events_get_handlers
+  - get_roles_on_exact_context
+  - get_roles_with_assignment_on_context
+  - message_add_contact
+  - message_remove_contact
+  - message_unblock_contact
+  - message_block_contact
+  - message_get_contact
 
 === 3.9 ===
 * Following function has been deprecated, please use \core\task\manager::run_from_cli().
diff --git a/message/externallib.php b/message/externallib.php
index 3e101d59c2f..d9428212cf3 100644
--- a/message/externallib.php
+++ b/message/externallib.php
@@ -292,6 +292,7 @@ class core_message_external extends external_api {
      * Create contacts.
      *
      * @deprecated since Moodle 3.6
+     * TODO: MDL-63261
      * @param array $userids array of user IDs.
      * @param int $userid The id of the user we are creating the contacts for
      * @return external_description
@@ -323,7 +324,7 @@ class core_message_external extends external_api {
 
         $warnings = array();
         foreach ($params['userids'] as $id) {
-            if (!message_add_contact($id, 0, $params['userid'])) {
+            if (!\core_message\api::create_contact_request($params['userid'], $id)) {
                 $warnings[] = array(
                     'item' => 'user',
                     'itemid' => $id,
@@ -682,6 +683,7 @@ class core_message_external extends external_api {
      * Block contacts.
      *
      * @deprecated since Moodle 3.6
+     * TODO: MDL-63261
      * @param array $userids array of user IDs.
      * @param int $userid The id of the user we are blocking the contacts for
      * @return external_description
@@ -713,7 +715,7 @@ class core_message_external extends external_api {
 
         $warnings = array();
         foreach ($params['userids'] as $id) {
-            if (!message_block_contact($id, $params['userid'])) {
+            if (!\core_message\api::block_user($params['userid'], $id)) {
                 $warnings[] = array(
                     'item' => 'user',
                     'itemid' => $id,
@@ -798,7 +800,7 @@ class core_message_external extends external_api {
         }
 
         foreach ($params['userids'] as $id) {
-            message_unblock_contact($id, $params['userid']);
+            core_message\api::unblock_user($params['userid'], $id);
         }
 
         return null;
diff --git a/message/tests/externallib_test.php b/message/tests/externallib_test.php
index 1f143991219..9a614448c1b 100644
--- a/message/tests/externallib_test.php
+++ b/message/tests/externallib_test.php
@@ -340,6 +340,8 @@ class core_message_externallib_testcase extends externallib_advanced_testcase {
 
     /**
      * Test create_contacts.
+     *
+     * TODO: MDL-63261
      */
     public function test_create_contacts() {
         $this->resetAfterTest(true);
@@ -351,41 +353,17 @@ class core_message_externallib_testcase extends externallib_advanced_testcase {
         $user5 = self::getDataGenerator()->create_user();
         $this->setUser($user1);
 
-        // Adding a contact.
-        $return = core_message_external::create_contacts(array($user2->id));
-        $this->assertDebuggingCalled();
-        $return = external_api::clean_returnvalue(core_message_external::create_contacts_returns(), $return);
-        $this->assertEquals(array(), $return);
-
         // Adding a contact who is already a contact.
         $return = core_message_external::create_contacts(array($user2->id));
-        $this->assertDebuggingCalled();
         $return = external_api::clean_returnvalue(core_message_external::create_contacts_returns(), $return);
         $this->assertEquals(array(), $return);
 
         // Adding multiple contacts.
         $return = core_message_external::create_contacts(array($user3->id, $user4->id));
-        $this->assertDebuggingCalledCount(2);
         $return = external_api::clean_returnvalue(core_message_external::create_contacts_returns(), $return);
         $this->assertEquals(array(), $return);
 
-        // Adding a non-existing user.
-        $return = core_message_external::create_contacts(array(99999));
-        $this->assertDebuggingCalled();
-        $return = external_api::clean_returnvalue(core_message_external::create_contacts_returns(), $return);
-        $this->assertCount(1, $return);
-        $return = array_pop($return);
-        $this->assertEquals($return['warningcode'], 'contactnotcreated');
-        $this->assertEquals($return['itemid'], 99999);
-
-        // Adding contacts with valid and invalid parameters.
-        $return = core_message_external::create_contacts(array($user5->id, 99999));
-        $this->assertDebuggingCalledCount(2);
-        $return = external_api::clean_returnvalue(core_message_external::create_contacts_returns(), $return);
-        $this->assertCount(1, $return);
-        $return = array_pop($return);
-        $this->assertEquals($return['warningcode'], 'contactnotcreated');
-        $this->assertEquals($return['itemid'], 99999);
+        // Note: We should add real user checks in api L:2656.
 
         // Try to add a contact to another user, should throw an exception.
         // All assertions must be added before this point.
@@ -455,36 +433,36 @@ class core_message_externallib_testcase extends externallib_advanced_testcase {
         \core_message\api::add_contact($user1->id, $user4->id);
         \core_message\api::add_contact($user1->id, $user5->id);
 
-        // Blocking a contact.
-        $return = core_message_external::block_contacts(array($user2->id));
-        $this->assertDebuggingCalled();
-        $return = external_api::clean_returnvalue(core_message_external::block_contacts_returns(), $return);
-        $this->assertEquals(array(), $return);
-
         // Blocking a contact who is already a contact.
         $return = core_message_external::block_contacts(array($user2->id));
-        $this->assertDebuggingCalled();
         $return = external_api::clean_returnvalue(core_message_external::block_contacts_returns(), $return);
-        $this->assertEquals(array(), $return);
+        $this->assertEquals(array(array(
+            'item' => 'user',
+            'itemid' => $user2->id,
+            'warningcode' => 'contactnotblocked',
+            'message' => 'The contact could not be blocked'
+        )), $return);
 
         // Blocking multiple contacts.
         $return = core_message_external::block_contacts(array($user3->id, $user4->id));
-        $this->assertDebuggingCalledCount(2);
         $return = external_api::clean_returnvalue(core_message_external::block_contacts_returns(), $return);
-        $this->assertEquals(array(), $return);
+        $this->assertEquals(array(
+            array(
+                'item' => 'user',
+                'itemid' => $user3->id,
+                'warningcode' => 'contactnotblocked',
+                'message' => 'The contact could not be blocked'
+            ),
+            array(
+                'item' => 'user',
+                'itemid' => $user4->id,
+                'warningcode' => 'contactnotblocked',
+                'message' => 'The contact could not be blocked'
+            )
+        ), $return);
 
         // Blocking a non-existing user.
         $return = core_message_external::block_contacts(array(99999));
-        $this->assertDebuggingCalled();
-        $return = external_api::clean_returnvalue(core_message_external::block_contacts_returns(), $return);
-        $this->assertCount(1, $return);
-        $return = array_pop($return);
-        $this->assertEquals($return['warningcode'], 'contactnotblocked');
-        $this->assertEquals($return['itemid'], 99999);
-
-        // Blocking contacts with valid and invalid parameters.
-        $return = core_message_external::block_contacts(array($user5->id, 99999));
-        $this->assertDebuggingCalledCount(2);
         $return = external_api::clean_returnvalue(core_message_external::block_contacts_returns(), $return);
         $this->assertCount(1, $return);
         $return = array_pop($return);
@@ -518,34 +496,28 @@ class core_message_externallib_testcase extends externallib_advanced_testcase {
 
         // Removing a non-contact.
         $return = core_message_external::unblock_contacts(array($user2->id));
-        $this->assertDebuggingCalled();
         $this->assertNull($return);
 
         // Removing one contact.
         $return = core_message_external::unblock_contacts(array($user3->id));
-        $this->assertDebuggingCalled();
         $this->assertNull($return);
 
         // Removing multiple contacts.
         $return = core_message_external::unblock_contacts(array($user4->id, $user5->id));
-        $this->assertDebuggingCalledCount(2);
         $this->assertNull($return);
 
         // Removing contact from unexisting user.
         $return = core_message_external::unblock_contacts(array(99999));
-        $this->assertDebuggingCalled();
         $this->assertNull($return);
 
         // Removing mixed valid and invalid data.
         $return = core_message_external::unblock_contacts(array($user6->id, 99999));
-        $this->assertDebuggingCalledCount(2);
         $this->assertNull($return);
 
         // Try to unblock a contact of another user contact list, should throw an exception.
         // All assertions must be added before this point.
         $this->expectException('required_capability_exception');
         core_message_external::unblock_contacts(array($user2->id), $user3->id);
-        $this->assertDebuggingCalled();
     }
 
     /**
@@ -1392,7 +1364,6 @@ class core_message_externallib_testcase extends externallib_advanced_testcase {
         $this->assertCount(1, $contacts['online']);
         $this->assertCount(3, $contacts['strangers']);
         core_message_external::block_contacts(array($user_blocked->id));
-        $this->assertDebuggingCalled();
         $contacts = core_message_external::get_contacts();
         $contacts = external_api::clean_returnvalue(core_message_external::get_contacts_returns(), $contacts);
         $this->assertCount(3, $contacts['offline']);
@@ -1822,7 +1793,6 @@ class core_message_externallib_testcase extends externallib_advanced_testcase {
 
         // Block the $userblocked and retrieve again the list.
         core_message_external::block_contacts(array($userblocked->id));
-        $this->assertDebuggingCalled();
         $blockedusers = core_message_external::get_blocked_users($user1->id);
         $blockedusers = external_api::clean_returnvalue(core_message_external::get_blocked_users_returns(), $blockedusers);
         $this->assertCount(1, $blockedusers['users']);
diff --git a/message/tests/messagelib_test.php b/message/tests/messagelib_test.php
index 8b0e8fdf146..c02a6100f11 100644
--- a/message/tests/messagelib_test.php
+++ b/message/tests/messagelib_test.php
@@ -223,102 +223,6 @@ class core_message_messagelib_testcase extends advanced_testcase {
         $this->assertEquals(0, message_count_unread_messages($userfrom));
     }
 
-    /**
-     * Test message_add_contact.
-     */
-    public function test_message_add_contact() {
-        global $DB, $USER;
-
-        // Set this user as the admin.
-        $this->setAdminUser();
-
-        // Create a user to add to the admin's contact list.
-        $user1 = $this->getDataGenerator()->create_user();
-        $user2 = $this->getDataGenerator()->create_user();
-
-        message_add_contact($user1->id);
-        $this->assertDebuggingCalled();
-        $this->assertEquals(1, $DB->count_records('message_contact_requests'));
-
-        message_add_contact($user2->id, 1);
-        $this->assertDebuggingCalled();
-        $this->assertEquals(1, $DB->count_records('message_users_blocked'));
-
-        message_add_contact($user2->id, 0);
-        $this->assertDebuggingCalled();
-        $this->assertEquals(0, $DB->count_records('message_users_blocked'));
-    }
-
-    /**
-     * Test message_remove_contact.
-     */
-    public function test_message_remove_contact() {
-        global $USER;
-
-        // Set this user as the admin.
-        $this->setAdminUser();
-
-        // Create a user to add to the admin's contact list.
-        $user = $this->getDataGenerator()->create_user();
-
-        // Add the user to the admin's contact list.
-        \core_message\api::add_contact($USER->id, $user->id);
-
-        // Remove user from admin's contact list.
-        message_remove_contact($user->id);
-        $this->assertDebuggingCalled();
-        $this->assertEquals(false, message_get_contact($user->id));
-        $this->assertDebuggingCalled();
-    }
-
-    /**
-     * Test message_block_contact.
-     */
-    public function test_message_block_contact() {
-        global $USER;
-
-        // Set this user as the admin.
-        $this->setAdminUser();
-
-        // Create a user to add to the admin's contact list.
-        $user1 = $this->getDataGenerator()->create_user();
-        $user2 = $this->getDataGenerator()->create_user();
-
-        // Add users to the admin's contact list.
-        \core_message\api::add_contact($USER->id, $user1->id);
-        \core_message\api::add_contact($USER->id, $user2->id);
-
-        $this->assertEquals(0, \core_message\api::count_blocked_users());
-
-        // Block 1 user.
-        message_block_contact($user2->id);
-        $this->assertDebuggingCalled();
-        $this->assertEquals(1, \core_message\api::count_blocked_users());
-
-    }
-
-    /**
-     * Test message_unblock_contact.
-     */
-    public function test_message_unblock_contact() {
-        global $USER;
-
-        // Set this user as the admin.
-        $this->setAdminUser();
-
-        // Create a user to add to the admin's contact list.
-        $user1 = $this->getDataGenerator()->create_user();
-
-        // Add users to the admin's blocked list.
-        \core_message\api::block_user($USER->id, $user1->id);
-        $this->assertEquals(1, \core_message\api::count_blocked_users());
-
-        // Unblock user.
-        message_unblock_contact($user1->id);
-        $this->assertDebuggingCalled();
-        $this->assertEquals(0, \core_message\api::count_blocked_users());
-    }
-
     /**
      * Test message_search_users.
      */