diff --git a/phpBB/includes/functions_content.php b/phpBB/includes/functions_content.php
index 2203694093..1b5fffc445 100644
--- a/phpBB/includes/functions_content.php
+++ b/phpBB/includes/functions_content.php
@@ -1210,6 +1210,7 @@ function parse_attachments($forum_id, &$message, &$attachments, &$update_count,
 			);
 		}
 
+		$update_count_ary = $update_count;
 		/**
 		* Use this event to modify the attachment template data.
 		*
@@ -1223,8 +1224,9 @@ function parse_attachments($forum_id, &$message, &$attachments, &$update_count,
 		* @var array	extensions		Array with attachment extensions data
 		* @var mixed 	forum_id 		The forum id the attachments are displayed in (false if in private message)
 		* @var bool		preview			Flag indicating if we are in post preview mode
-		* @var array	update_count	Array with attachment ids to update download count
+		* @var array	update_count_ary	Array with attachment ids to update download count
 		* @since 3.1.0-RC5
+		* @change 3.1.7-RC1 Replaced update_count with update_count_ary
 		*/
 		$vars = array(
 			'attachment',
@@ -1234,9 +1236,11 @@ function parse_attachments($forum_id, &$message, &$attachments, &$update_count,
 			'extensions',
 			'forum_id',
 			'preview',
-			'update_count',
+			'update_count_ary',
 		);
 		extract($phpbb_dispatcher->trigger_event('core.parse_attachments_modify_template_data', compact($vars)));
+		$update_count = $update_count_ary;
+		unset($update_count_ary);
 
 		$template->assign_block_vars('_file', $block_array);
 
diff --git a/phpBB/includes/functions_display.php b/phpBB/includes/functions_display.php
index 3d61b5c098..0143a2b9ab 100644
--- a/phpBB/includes/functions_display.php
+++ b/phpBB/includes/functions_display.php
@@ -438,15 +438,14 @@ function display_forums($root_data = '', $display_moderators = true, $return_mod
 			*
 			* @event core.display_forums_modify_category_template_vars
 			* @var	array	cat_row			Template data of the 'category'
-			* @var	bool	catless			The flag indicating whether the 'category' has a parent category
 			* @var	bool	last_catless	The flag indicating whether the last forum had a parent category
 			* @var	array	root_data		Array with the root forum data
 			* @var	array	row				The data of the 'category'
 			* @since 3.1.0-RC4
+			* @change 3.1.7-RC1 Removed undefined catless variable
 			*/
 			$vars = array(
 				'cat_row',
-				'catless',
 				'last_catless',
 				'root_data',
 				'row',
@@ -811,25 +810,29 @@ function generate_forum_nav(&$forum_data)
 		'S_ENABLE_FEEDS_FORUM'	=> ($config['feed_forum'] && $forum_data['forum_type'] == FORUM_POST && !phpbb_optionget(FORUM_OPTION_FEED_EXCLUDE, $forum_data['forum_options'])) ? true : false,
 	);
 
+	$forum_data_ary = $forum_data;
 	/**
 	* Event to modify the navlinks text
 	*
 	* @event core.generate_forum_nav
-	* @var	array	forum_data				Array with the forum data
+	* @var	array	forum_data_ary				Array with the forum data
 	* @var	array	forum_template_data		Array with generic forum template data
 	* @var	string	microdata_attr			The microdata attribute
 	* @var	array	navlinks_parents		Array with the forum parents navlinks data
 	* @var	array	navlinks				Array with the forum navlinks data
 	* @since 3.1.5-RC1
+	* @change 3.2.0-a1 Replaced forum_data with forum_data_ary
 	*/
 	$vars = array(
-		'forum_data',
+		'forum_data_ary',
 		'forum_template_data',
 		'microdata_attr',
 		'navlinks_parents',
 		'navlinks',
 	);
 	extract($phpbb_dispatcher->trigger_event('core.generate_forum_nav', compact($vars)));
+	$forum_data = $forum_data_ary;
+	unset($forum_data_ary);
 
 	$template->assign_block_vars_array('navlinks', $navlinks_parents);
 	$template->assign_block_vars('navlinks', $navlinks);
@@ -1237,17 +1240,21 @@ function display_user_activity(&$userdata)
 		}
 	}
 
+	$userdata_ary = $userdata;
 	/**
 	* Alter list of forums and topics to display as active
 	*
 	* @event core.display_user_activity_modify_actives
-	* @var	array	userdata						User's data
+	* @var	array	userdata_ary					User's data
 	* @var	array	active_f_row					List of active forums
 	* @var	array	active_t_row					List of active posts
 	* @since 3.1.0-RC3
+	* @change 3.1.7-RC1 Replaced userdata with userdata_ary
 	*/
-	$vars = array('userdata', 'active_f_row', 'active_t_row');
+	$vars = array('userdata_ary', 'active_f_row', 'active_t_row');
 	extract($phpbb_dispatcher->trigger_event('core.display_user_activity_modify_actives', compact($vars)));
+	$userdata = $userdata_ary;
+	unset($userdata_ary);
 
 	$userdata['active_t_row'] = $active_t_row;
 	$userdata['active_f_row'] = $active_f_row;