diff --git a/.gitignore b/.gitignore
index 13cfa16ebf..10a4e85c2e 100644
--- a/.gitignore
+++ b/.gitignore
@@ -21,6 +21,8 @@ node_modules
 /phpBB/vendor
 /phpBB/vendor-ext/*
 !/phpBB/vendor-ext/.git-keep
+/phpBB/composer-ext.json
+/phpBB/composer-ext.lock
 /tests/phpbb_unit_tests.sqlite*
 /tests/test_config*.php
 /tests/tmp/*
diff --git a/phpBB/bin/phpbbcli.php b/phpBB/bin/phpbbcli.php
index 1b3fac51e0..d007ab3914 100755
--- a/phpBB/bin/phpbbcli.php
+++ b/phpBB/bin/phpbbcli.php
@@ -71,7 +71,7 @@ require($phpbb_root_path . 'includes/compatibility_globals.' . $phpEx);
 
 register_compatibility_globals();
 
-if (is_file($phpbb_root_path . $config['exts_composer_vendor_dir'] . '/autoload.php'))
+if (@is_file($phpbb_root_path . $config['exts_composer_vendor_dir'] . '/autoload.php'))
 {
 	require_once($phpbb_root_path . $config['exts_composer_vendor_dir'] . '/autoload.php');
 }
diff --git a/phpBB/common.php b/phpBB/common.php
index 30293cae51..ea386978fb 100644
--- a/phpBB/common.php
+++ b/phpBB/common.php
@@ -141,7 +141,7 @@ require($phpbb_root_path . 'includes/compatibility_globals.' . $phpEx);
 
 register_compatibility_globals();
 
-if (is_file($phpbb_root_path . $config['exts_composer_vendor_dir'] . '/autoload.php'))
+if (@is_file($phpbb_root_path . $config['exts_composer_vendor_dir'] . '/autoload.php'))
 {
 	require_once($phpbb_root_path . $config['exts_composer_vendor_dir'] . '/autoload.php');
 }
diff --git a/phpBB/composer-ext.json b/phpBB/composer-ext.json
index 8194460949..e69de29bb2 100644
--- a/phpBB/composer-ext.json
+++ b/phpBB/composer-ext.json
@@ -1,160 +0,0 @@
-{
-    "require": {
-        "php": ">=5.5.9",
-        "bantu/ini-get-wrapper": "v1.0.1",
-        "google/recaptcha": "1.1.2",
-        "lusitanian/oauth": "v0.8.9",
-        "patchwork/utf8": "v1.1.31",
-        "psr/log": "1.0.0",
-        "ocramius/proxy-manager": "1.0.2",
-        "phing/phing": "2.4.14",
-        "sebastian/version": "1.0.6",
-        "sebastian/recursion-context": "1.0.2",
-        "sebastian/diff": "1.4.1",
-        "sebastian/comparator": "1.2.0",
-        "phpunit/php-text-template": "1.2.1",
-        "phpunit/php-token-stream": "1.4.8",
-        "phpunit/php-code-coverage": "2.2.4",
-        "paragonie/random_compat": "v1.4.1",
-        "symfony/polyfill-mbstring": "v1.2.0",
-        "squizlabs/php_codesniffer": "2.6.2",
-        "twig/twig": "v1.24.1",
-        "sebastian/exporter": "1.2.2",
-        "sebastian/environment": "1.3.7",
-        "phpunit/php-timer": "1.0.8",
-        "marc1706/fast-image-size": "v1.1.1",
-        "s9e/text-formatter": "0.6.2",
-        "guzzlehttp/psr7": "1.3.1",
-        "guzzlehttp/promises": "1.2.0",
-        "guzzlehttp/guzzle": "6.2.1",
-        "fabpot/goutte": "v3.1.2",
-        "facebook/webdriver": "1.1.1",
-        "symfony/process": "v3.1.3",
-        "laravel/homestead": "v3.0.2",
-        "sebastian/global-state": "1.1.1",
-        "doctrine/instantiator": "1.0.5",
-        "phpunit/phpunit-mock-objects": "2.3.8",
-        "phpunit/php-file-iterator": "1.4.1",
-        "phpdocumentor/reflection-common": "1.0",
-        "phpdocumentor/type-resolver": "0.2",
-        "phpdocumentor/reflection-docblock": "3.1.0",
-        "phpspec/prophecy": "v1.6.1",
-        "phpunit/phpunit": "4.8.27",
-        "phpunit/dbunit": "2.0.2",
-        "zendframework/zend-eventmanager": "3.0.1",
-        "zendframework/zend-code": "2.6.3",
-        "psr/http-message": "1.0",
-        "symfony/filesystem": "v3.1.3",
-        "symfony/config": "v3.1.3",
-        "symfony/http-foundation": "v3.1.3",
-        "symfony/event-dispatcher": "v3.1.3",
-        "symfony/debug": "v3.1.3",
-        "symfony/http-kernel": "v3.1.3",
-        "symfony/dependency-injection": "v3.1.3",
-        "symfony/proxy-manager-bridge": "v3.1.3",
-        "symfony/routing": "v3.1.3",
-        "symfony/twig-bridge": "v3.1.3",
-        "symfony/yaml": "v3.1.3",
-        "symfony/dom-crawler": "v3.1.3",
-        "symfony/browser-kit": "v3.1.3",
-        "symfony/css-selector": "v3.1.3",
-        "webmozart/assert": "1.0.2",
-        "symfony/finder": "v3.1.3",
-        "symfony/console": "v3.1.3",
-        "seld/phar-utils": "1.0.1",
-        "seld/jsonlint": "1.4.0",
-        "seld/cli-prompt": "1.0.2",
-        "justinrainbow/json-schema": "2.0.5",
-        "composer/spdx-licenses": "1.1.4",
-        "composer/semver": "1.4.2",
-        "composer/ca-bundle": "1.0.3",
-        "composer/composer": "1.2.0",
-        "phpbb/phpbb": "3.2.0-RC1",
-        "crizzo/aboutus": "*",
-        "phpbb/autogroups": "*"
-    },
-    "replace": {
-        "bantu/ini-get-wrapper": "v1.0.1",
-        "google/recaptcha": "1.1.2",
-        "lusitanian/oauth": "v0.8.9",
-        "patchwork/utf8": "v1.1.31",
-        "psr/log": "1.0.0",
-        "ocramius/proxy-manager": "1.0.2",
-        "phing/phing": "2.4.14",
-        "sebastian/version": "1.0.6",
-        "sebastian/recursion-context": "1.0.2",
-        "sebastian/diff": "1.4.1",
-        "sebastian/comparator": "1.2.0",
-        "phpunit/php-text-template": "1.2.1",
-        "phpunit/php-token-stream": "1.4.8",
-        "phpunit/php-code-coverage": "2.2.4",
-        "paragonie/random_compat": "v1.4.1",
-        "symfony/polyfill-mbstring": "v1.2.0",
-        "squizlabs/php_codesniffer": "2.6.2",
-        "twig/twig": "v1.24.1",
-        "sebastian/exporter": "1.2.2",
-        "sebastian/environment": "1.3.7",
-        "phpunit/php-timer": "1.0.8",
-        "marc1706/fast-image-size": "v1.1.1",
-        "s9e/text-formatter": "0.6.2",
-        "guzzlehttp/psr7": "1.3.1",
-        "guzzlehttp/promises": "1.2.0",
-        "guzzlehttp/guzzle": "6.2.1",
-        "fabpot/goutte": "v3.1.2",
-        "facebook/webdriver": "1.1.1",
-        "symfony/process": "v3.1.3",
-        "laravel/homestead": "v3.0.2",
-        "sebastian/global-state": "1.1.1",
-        "doctrine/instantiator": "1.0.5",
-        "phpunit/phpunit-mock-objects": "2.3.8",
-        "phpunit/php-file-iterator": "1.4.1",
-        "phpdocumentor/reflection-common": "1.0",
-        "phpdocumentor/type-resolver": "0.2",
-        "phpdocumentor/reflection-docblock": "3.1.0",
-        "phpspec/prophecy": "v1.6.1",
-        "phpunit/phpunit": "4.8.27",
-        "phpunit/dbunit": "2.0.2",
-        "zendframework/zend-eventmanager": "3.0.1",
-        "zendframework/zend-code": "2.6.3",
-        "psr/http-message": "1.0",
-        "symfony/filesystem": "v3.1.3",
-        "symfony/config": "v3.1.3",
-        "symfony/http-foundation": "v3.1.3",
-        "symfony/event-dispatcher": "v3.1.3",
-        "symfony/debug": "v3.1.3",
-        "symfony/http-kernel": "v3.1.3",
-        "symfony/dependency-injection": "v3.1.3",
-        "symfony/proxy-manager-bridge": "v3.1.3",
-        "symfony/routing": "v3.1.3",
-        "symfony/twig-bridge": "v3.1.3",
-        "symfony/yaml": "v3.1.3",
-        "symfony/dom-crawler": "v3.1.3",
-        "symfony/browser-kit": "v3.1.3",
-        "symfony/css-selector": "v3.1.3",
-        "webmozart/assert": "1.0.2",
-        "symfony/finder": "v3.1.3",
-        "symfony/console": "v3.1.3",
-        "seld/phar-utils": "1.0.1",
-        "seld/jsonlint": "1.4.0",
-        "seld/cli-prompt": "1.0.2",
-        "justinrainbow/json-schema": "2.0.5",
-        "composer/spdx-licenses": "1.1.4",
-        "composer/semver": "1.4.2",
-        "composer/ca-bundle": "1.0.3",
-        "composer/composer": "1.2.0",
-        "phpbb/phpbb": "3.2.0-RC1"
-    },
-    "repositories": [
-        {
-            "packagist": false
-        },
-        {
-            "type": "composer",
-            "url": "https://www.phpbb.com/customise/db/composer/"
-        }
-    ],
-    "config": {
-        "vendor-dir": "vendor-ext/"
-    },
-    "minimum-stability": "stable"
-}
diff --git a/phpBB/composer-ext.lock b/phpBB/composer-ext.lock
index e26a1065b5..e69de29bb2 100644
--- a/phpBB/composer-ext.lock
+++ b/phpBB/composer-ext.lock
@@ -1,257 +0,0 @@
-{
-    "_readme": [
-        "This file locks the dependencies of your project to a known state",
-        "Read more about it at https://getcomposer.org/doc/01-basic-usage.md#composer-lock-the-lock-file",
-        "This file is @generated automatically"
-    ],
-    "hash": "bc644abe8f4679d245f64777bddac9f2",
-    "content-hash": "bf9b94509582458eddbadef8384bfdf5",
-    "packages": [
-        {
-            "name": "composer/installers",
-            "version": "v1.2.0",
-            "source": {
-                "type": "git",
-                "url": "https://github.com/composer/installers.git",
-                "reference": "d78064c68299743e0161004f2de3a0204e33b804"
-            },
-            "dist": {
-                "type": "zip",
-                "url": "https://api.github.com/repos/composer/installers/zipball/d78064c68299743e0161004f2de3a0204e33b804",
-                "reference": "d78064c68299743e0161004f2de3a0204e33b804",
-                "shasum": ""
-            },
-            "require": {
-                "composer-plugin-api": "^1.0"
-            },
-            "replace": {
-                "roundcube/plugin-installer": "*",
-                "shama/baton": "*"
-            },
-            "require-dev": {
-                "composer/composer": "1.0.*@dev",
-                "phpunit/phpunit": "4.1.*"
-            },
-            "type": "composer-plugin",
-            "extra": {
-                "class": "Composer\\Installers\\Plugin",
-                "branch-alias": {
-                    "dev-master": "1.0-dev"
-                }
-            },
-            "autoload": {
-                "psr-4": {
-                    "Composer\\Installers\\": "src/Composer/Installers"
-                }
-            },
-            "notification-url": "https://packagist.org/downloads/",
-            "license": [
-                "MIT"
-            ],
-            "authors": [
-                {
-                    "name": "Kyle Robinson Young",
-                    "email": "kyle@dontkry.com",
-                    "homepage": "https://github.com/shama"
-                }
-            ],
-            "description": "A multi-framework Composer library installer",
-            "homepage": "https://composer.github.io/installers/",
-            "keywords": [
-                "Craft",
-                "Dolibarr",
-                "Hurad",
-                "ImageCMS",
-                "MODX Evo",
-                "Mautic",
-                "OXID",
-                "Plentymarkets",
-                "RadPHP",
-                "SMF",
-                "Thelia",
-                "WolfCMS",
-                "agl",
-                "aimeos",
-                "annotatecms",
-                "attogram",
-                "bitrix",
-                "cakephp",
-                "chef",
-                "cockpit",
-                "codeigniter",
-                "concrete5",
-                "croogo",
-                "dokuwiki",
-                "drupal",
-                "elgg",
-                "expressionengine",
-                "fuelphp",
-                "grav",
-                "installer",
-                "joomla",
-                "kohana",
-                "laravel",
-                "lithium",
-                "magento",
-                "mako",
-                "mediawiki",
-                "modulework",
-                "moodle",
-                "phpbb",
-                "piwik",
-                "ppi",
-                "puppet",
-                "reindex",
-                "roundcube",
-                "shopware",
-                "silverstripe",
-                "symfony",
-                "typo3",
-                "wordpress",
-                "yawik",
-                "zend",
-                "zikula"
-            ],
-            "time": "2016-08-13 20:53:52"
-        },
-        {
-            "name": "crizzo/aboutus",
-            "version": "2.0.4",
-            "dist": {
-                "type": "zip",
-                "url": "https://www.phpbb.com/customise/db/download/121131/composer",
-                "reference": null,
-                "shasum": null
-            },
-            "require": {
-                "php": ">=5.3.3"
-            },
-            "type": "phpbb-extension",
-            "extra": {
-                "display-name": "About us",
-                "soft-require": {
-                    "phpbb/phpbb": ">=3.1.2"
-                },
-                "version-check": {
-                    "host": "www.phpbb.com",
-                    "directory": "/customise/db/extension/about_us",
-                    "filename": "version_check"
-                }
-            },
-            "license": [
-                "GPL-2.0"
-            ],
-            "authors": [
-                {
-                    "name": "Christian Schnegelberger",
-                    "username": "Crizzo",
-                    "email": "kontakt@crizzo.de",
-                    "homepage": "http://www.crizzo.de",
-                    "role": "Developer/Founder"
-                }
-            ],
-            "description": "About us is an extension which adds to phpBB 3.1 a about us or legal notice-page, where you can add your contact details and more.",
-            "homepage": "https://www.phpbb.com/customise/db/extension/about_us/",
-            "time": "2015-10-23 00:00:00"
-        },
-        {
-            "name": "phpbb/autogroups",
-            "version": "1.0.1",
-            "dist": {
-                "type": "zip",
-                "url": "https://api.github.com/repos/phpbb-extensions/autogroups/zipball/38ffd4dfaa839310f42be43b32075c8237f239d0",
-                "reference": "38ffd4dfaa839310f42be43b32075c8237f239d0",
-                "shasum": ""
-            },
-            "require": {
-                "composer/installers": "~1.0",
-                "php": ">=5.3.3"
-            },
-            "require-dev": {
-                "phing/phing": "2.4.*",
-                "phpbb/epv": "dev-master"
-            },
-            "type": "phpbb-extension",
-            "extra": {
-                "display-name": "Auto Groups",
-                "soft-require": {
-                    "phpbb/phpbb": ">=3.1.0,<3.2.*@dev"
-                },
-                "version-check": {
-                    "host": "www.phpbb.com",
-                    "directory": "/customise/db/extension/auto_groups",
-                    "filename": "version_check"
-                }
-            },
-            "notification-url": "https://packagist.org/downloads/",
-            "license": [
-                "GPL-2.0"
-            ],
-            "authors": [
-                {
-                    "name": "Michael Cullum",
-                    "email": "michael@phpbb.com",
-                    "homepage": "http://michaelcullum.com",
-                    "role": "Extensions Team Consultant"
-                },
-                {
-                    "name": "Marc Alexander",
-                    "email": "admin@m-a-styles.de",
-                    "homepage": "http://www.m-a-styles.de",
-                    "role": "Extensions Team Consultant"
-                },
-                {
-                    "name": "Matt Friedman",
-                    "homepage": "http://mattfriedman.me",
-                    "role": "Extensions Development Team Lead"
-                },
-                {
-                    "name": "Nathan Guse",
-                    "email": "nathaniel.guse@gmail.com",
-                    "role": "Former Extensions Development Team Lead"
-                },
-                {
-                    "name": "Clemens Husung",
-                    "email": "wolfsblvt@pinkes-forum.de",
-                    "role": "Extensions Development Team"
-                },
-                {
-                    "name": "Lukasz Kaczynski",
-                    "role": "Former Extensions Development Team Member"
-                },
-                {
-                    "name": "John Peskens",
-                    "email": "info@forumhulp.com",
-                    "homepage": "http://forumhulp.com",
-                    "role": "Former Extensions Development Team Member"
-                },
-                {
-                    "name": "Ruslan Uzdenov",
-                    "homepage": "http://www.phpbbguru.net",
-                    "role": "Extensions Development Team"
-                }
-            ],
-            "description": "An extension that can automate the process of adding and removing users from groups upon reaching specified milestones related to their post count, age, membership, and warnings count.",
-            "homepage": "https://www.phpbb.com",
-            "keywords": [
-                "auto",
-                "extension",
-                "groups",
-                "phpbb"
-            ],
-            "time": "2015-09-05 17:30:29"
-        }
-    ],
-    "packages-dev": [],
-    "aliases": [],
-    "minimum-stability": "stable",
-    "stability-flags": {
-        "phpbb/phpbb": 5
-    },
-    "prefer-stable": true,
-    "prefer-lowest": false,
-    "platform": {
-        "php": ">=5.5.9"
-    },
-    "platform-dev": []
-}
diff --git a/phpBB/download/file.php b/phpBB/download/file.php
index fbbabfb74f..858dfd2c32 100644
--- a/phpBB/download/file.php
+++ b/phpBB/download/file.php
@@ -99,7 +99,7 @@ if (isset($_GET['avatar']))
 	/* @var $phpbb_avatar_manager \phpbb\avatar\manager */
 	$phpbb_avatar_manager = $phpbb_container->get('avatar.manager');
 
-	if (is_file($phpbb_root_path . $config['exts_composer_vendor_dir'] . '/autoload.php'))
+	if (@is_file($phpbb_root_path . $config['exts_composer_vendor_dir'] . '/autoload.php'))
 	{
 		require_once($phpbb_root_path . $config['exts_composer_vendor_dir'] . '/autoload.php');
 	}
diff --git a/phpBB/includes/acp/acp_extensions.php b/phpBB/includes/acp/acp_extensions.php
index 949683e6b4..70fb763d8d 100644
--- a/phpBB/includes/acp/acp_extensions.php
+++ b/phpBB/includes/acp/acp_extensions.php
@@ -24,7 +24,7 @@ if (!defined('IN_PHPBB'))
 
 class acp_extensions
 {
-	var $u_action;
+	public $u_action;
 
 	private $db;
 
diff --git a/phpBB/language/en/acp/extensions.php b/phpBB/language/en/acp/extensions.php
index 66bb5ca8ac..c6eb147b86 100644
--- a/phpBB/language/en/acp/extensions.php
+++ b/phpBB/language/en/acp/extensions.php
@@ -152,16 +152,16 @@ $lang = array_merge($lang, array(
 	'META_FIELD_INVALID'	=> 'Meta field %s is invalid.',
 
 	'EXTENSIONS_CATALOG_SETTINGS'	=> 'Extensions catalog settings',
-	'ENABLE_ON_INSTALL'				=> 'Enable extensions when installing',
-	'PURGE_ON_REMOVE'				=> 'Purge extensions when removing',
-	'ENABLE_PACKAGIST'				=> 'Enable Packagist usage',
-	'ENABLE_PACKAGIST_EXPLAIN'		=> 'Use packagist to browse extensions? Beware that packagist may contain extensions not validated by phpBB.',
-	'ENABLE_PACKAGIST_CONFIRM'		=> 'Are you sure you want to enable packagist?',
+	'ENABLE_ON_INSTALL'				=> 'Enable extensions while installing',
+	'PURGE_ON_REMOVE'				=> 'Purge extensions while removing',
+	'ENABLE_PACKAGIST'				=> 'Search packagist',
+	'ENABLE_PACKAGIST_EXPLAIN'		=> 'Search packagist for phpBB extensions. Beware that packagist may contain extensions not validated by the phpBB Extension Customisations Team.',
+	'ENABLE_PACKAGIST_CONFIRM'		=> 'Are you sure you want to search packagist?',
 	'COMPOSER_REPOSITORIES'			=> 'Repositories',
-	'COMPOSER_REPOSITORIES_EXPLAIN'	=> 'List of composer repositories (must be the base url of the packages.json file), one per line.',
-	'NO_EXTENSION_AVAILABLE'		=> 'There is no extension available for your board',
+	'COMPOSER_REPOSITORIES_EXPLAIN'	=> 'Add URLs to Composer repositories of phpBB extensions to search here, one per line (must be the base url of the packages.json file).',
+	'NO_EXTENSION_AVAILABLE'		=> 'There are no extension available for your board',
 
-	'EXTENSION_MANAGED_SUCCESS'		=> 'The extension %s is now managed automatically.',
+	'EXTENSION_MANAGED_SUCCESS'		=> 'The extension %s is now being managed automatically.',
 	'EXTENSIONS_INSTALLED'			=> 'Extensions successfully installed.',
 	'EXTENSIONS_REMOVED'			=> 'Extensions successfully removed.',
 	'EXTENSIONS_UPDATED'			=> 'Extensions successfully updated.',
diff --git a/phpBB/phpbb/composer/io/html_output_formatter.php b/phpBB/phpbb/composer/io/html_output_formatter.php
index 1629e1895c..588be30a21 100644
--- a/phpBB/phpbb/composer/io/html_output_formatter.php
+++ b/phpBB/phpbb/composer/io/html_output_formatter.php
@@ -41,9 +41,6 @@ class html_output_formatter extends \Composer\Console\HtmlOutputFormatter
 		= [
 			1 => 'bold',
 			4 => 'underscore',
-			//5 => 'blink',
-			//7 => 'reverse',
-			//8 => 'conceal'
 		];
 
 	/**
diff --git a/phpBB/phpbb/composer/manager.php b/phpBB/phpbb/composer/manager.php
index b75bcad3d7..43ea8a2503 100644
--- a/phpBB/phpbb/composer/manager.php
+++ b/phpBB/phpbb/composer/manager.php
@@ -253,7 +253,7 @@ class manager implements manager_interface
 		{
 			$this->available_packages = $this->cache->get('_composer_' . $this->package_type . '_available');
 
-			if (true || !$this->available_packages)
+			if (!$this->available_packages)
 			{
 				$this->available_packages = $this->installer->get_available_packages($this->package_type);
 				$this->cache->put('_composer_' . $this->package_type . '_available', $this->available_packages, 24*60*60);
diff --git a/phpBB/phpbb/db/migration/data/v320/extensions_composer.php b/phpBB/phpbb/db/migration/data/v330/extensions_composer.php
similarity index 96%
rename from phpBB/phpbb/db/migration/data/v320/extensions_composer.php
rename to phpBB/phpbb/db/migration/data/v330/extensions_composer.php
index 957d141683..7e12150e56 100644
--- a/phpBB/phpbb/db/migration/data/v320/extensions_composer.php
+++ b/phpBB/phpbb/db/migration/data/v330/extensions_composer.php
@@ -11,7 +11,7 @@
 *
 */
 
-namespace phpbb\db\migration\data\v320;
+namespace phpbb\db\migration\data\v330;
 
 class extensions_composer extends \phpbb\db\migration\migration
 {
diff --git a/phpBB/phpbb/di/container_builder.php b/phpBB/phpbb/di/container_builder.php
index 08400320b7..c4cb64144b 100644
--- a/phpBB/phpbb/di/container_builder.php
+++ b/phpBB/phpbb/di/container_builder.php
@@ -416,7 +416,7 @@ class container_builder
 			$ext_container->compile();
 
 			$config = $ext_container->get('config');
-			if (is_file($this->phpbb_root_path . $config['exts_composer_vendor_dir'] . '/autoload.php'))
+			if (@is_file($this->phpbb_root_path . $config['exts_composer_vendor_dir'] . '/autoload.php'))
 			{
 				require_once($this->phpbb_root_path . $config['exts_composer_vendor_dir'] . '/autoload.php');
 			}