diff --git a/.github/workflows/ember.yml b/.github/workflows/ember.yml
index 07080e58e4..538b16b316 100644
--- a/.github/workflows/ember.yml
+++ b/.github/workflows/ember.yml
@@ -9,7 +9,7 @@ on:
 jobs:
   build:
     name: run
-    if: false # something is broken with this job so skip for now
+    if: true
     runs-on: ubuntu-latest
     container: discourse/discourse_test:release
     timeout-minutes: 40
diff --git a/Gemfile b/Gemfile
index 48f7879ff6..9c2ff7cdbb 100644
--- a/Gemfile
+++ b/Gemfile
@@ -105,7 +105,10 @@ gem 'omniauth-oauth2', require: false
 
 gem 'omniauth-google-oauth2'
 
-gem 'oj'
+# Pinning oj until https://github.com/ohler55/oj/issues/699 is resolved.
+# Segfaults and stuck processes after upgrading.
+gem 'oj', '3.13.2'
+
 gem 'pg'
 gem 'mini_sql'
 gem 'pry-rails', require: false
diff --git a/Gemfile.lock b/Gemfile.lock
index 1aed5f27eb..152aabb99e 100644
--- a/Gemfile.lock
+++ b/Gemfile.lock
@@ -52,7 +52,7 @@ GEM
       activerecord (>= 3.2, < 7.0)
       rake (>= 10.4, < 14.0)
     ast (2.4.2)
-    aws-eventstream (1.1.1)
+    aws-eventstream (1.2.0)
     aws-partitions (1.432.0)
     aws-sdk-core (3.112.1)
       aws-eventstream (~> 1, >= 1.0.2)
@@ -158,7 +158,7 @@ GEM
     fast_blank (1.0.1)
     fast_xs (0.8.0)
     fastimage (2.2.5)
-    ffi (1.15.3)
+    ffi (1.15.4)
     fspath (3.1.2)
     gc_tracer (1.5.1)
     globalid (0.5.2)
@@ -550,7 +550,7 @@ DEPENDENCIES
   multi_json
   mustache
   nokogiri
-  oj
+  oj (= 3.13.2)
   omniauth
   omniauth-facebook
   omniauth-github
@@ -609,4 +609,4 @@ DEPENDENCIES
   yaml-lint
 
 BUNDLED WITH
-   2.2.19
+   2.2.26
diff --git a/app/assets/javascripts/discourse/app/components/composer-editor.js b/app/assets/javascripts/discourse/app/components/composer-editor.js
index c319408bbc..eb2d079853 100644
--- a/app/assets/javascripts/discourse/app/components/composer-editor.js
+++ b/app/assets/javascripts/discourse/app/components/composer-editor.js
@@ -219,6 +219,8 @@ export default Component.extend(ComposerUpload, {
     }
 
     this._bindUploadTarget();
+    this._bindMobileUploadButton();
+
     this.appEvents.trigger("composer:will-open");
   },
 
@@ -607,6 +609,7 @@ export default Component.extend(ComposerUpload, {
 
   @on("willDestroyElement")
   _composerClosed() {
+    this._unbindMobileUploadButton();
     this.appEvents.trigger("composer:will-close");
     next(() => {
       // need to wait a bit for the "slide down" transition of the composer
diff --git a/app/assets/javascripts/discourse/app/lib/plugin-api.js b/app/assets/javascripts/discourse/app/lib/plugin-api.js
index 71a6210d91..35877fa5aa 100644
--- a/app/assets/javascripts/discourse/app/lib/plugin-api.js
+++ b/app/assets/javascripts/discourse/app/lib/plugin-api.js
@@ -86,6 +86,25 @@ import { addSearchSuggestion } from "discourse/widgets/search-menu-results";
 // If you add any methods to the API ensure you bump up this number
 const PLUGIN_API_VERSION = "0.12.2";
 
+// This helper prevents us from applying the same `modifyClass` over and over in test mode.
+function canModify(klass, type, resolverName, changes) {
+  if (!changes.pluginId) {
+    // eslint-disable-next-line no-console
+    console.warn(
+      "To prevent errors, add a `pluginId` key to your changes when calling `modifyClass`"
+    );
+    return true;
+  }
+
+  let key = "_" + type + "/" + changes.pluginId + "/" + resolverName;
+  if (klass.class[key]) {
+    return false;
+  } else {
+    klass.class[key] = 1;
+    return true;
+  }
+}
+
 class PluginApi {
   constructor(version, container) {
     this.version = version;
@@ -138,10 +157,14 @@ class PluginApi {
   /**
    * Allows you to overwrite or extend methods in a class.
    *
+   * You should add a `pluginId` property to identify your plugin
+   * to help Discourse reload classes properly.
+   *
    * For example:
    *
    * ```
    * api.modifyClass('controller:composer', {
+   *   pluginId: 'my-plugin',
    *   actions: {
    *     newActionHere() { }
    *   }
@@ -150,9 +173,15 @@ class PluginApi {
    **/
   modifyClass(resolverName, changes, opts) {
     const klass = this._resolveClass(resolverName, opts);
-    if (klass) {
+    if (!klass) {
+      return;
+    }
+
+    if (canModify(klass, "member", resolverName, changes)) {
+      delete changes.pluginId;
       klass.class.reopen(changes);
     }
+
     return klass;
   }
 
@@ -169,9 +198,15 @@ class PluginApi {
    **/
   modifyClassStatic(resolverName, changes, opts) {
     const klass = this._resolveClass(resolverName, opts);
-    if (klass) {
+    if (!klass) {
+      return;
+    }
+
+    if (canModify(klass, "static", resolverName, changes)) {
+      delete changes.pluginId;
       klass.class.reopenClass(changes);
     }
+
     return klass;
   }
 
diff --git a/app/assets/javascripts/discourse/app/mixins/composer-upload-uppy.js b/app/assets/javascripts/discourse/app/mixins/composer-upload-uppy.js
index 885c86b3f9..788a4416ee 100644
--- a/app/assets/javascripts/discourse/app/mixins/composer-upload-uppy.js
+++ b/app/assets/javascripts/discourse/app/mixins/composer-upload-uppy.js
@@ -46,11 +46,6 @@ export default Mixin.create({
 
   @on("willDestroyElement")
   _unbindUploadTarget() {
-    this.mobileUploadButton?.removeEventListener(
-      "click",
-      this.mobileUploadButtonEventListener
-    );
-
     this.fileInputEl?.removeEventListener(
       "change",
       this.fileInputEventListener
@@ -86,7 +81,6 @@ export default Mixin.create({
     this._unbindUploadTarget();
     this._bindFileInputChangeListener();
     this._bindPasteListener();
-    this._bindMobileUploadButton();
 
     this._uppyInstance = new Uppy({
       id: this.uppyId,
@@ -153,6 +147,10 @@ export default Mixin.create({
     });
 
     this._uppyInstance.on("progress", (progress) => {
+      if (this.isDestroying || this.isDestroyed) {
+        return;
+      }
+
       this.set("uploadProgress", progress);
     });
 
diff --git a/app/assets/javascripts/discourse/app/mixins/composer-upload.js b/app/assets/javascripts/discourse/app/mixins/composer-upload.js
index c3ada1ccc0..01ab335dda 100644
--- a/app/assets/javascripts/discourse/app/mixins/composer-upload.js
+++ b/app/assets/javascripts/discourse/app/mixins/composer-upload.js
@@ -327,8 +327,6 @@ export default Mixin.create({
         }
       });
     });
-
-    this._bindMobileUploadButton();
   },
 
   _bindMobileUploadButton() {
@@ -345,13 +343,15 @@ export default Mixin.create({
     }
   },
 
-  @on("willDestroyElement")
-  _unbindUploadTarget() {
+  _unbindMobileUploadButton() {
     this.mobileUploadButton?.removeEventListener(
       "click",
       this.mobileUploadButtonEventListener
     );
+  },
 
+  @on("willDestroyElement")
+  _unbindUploadTarget() {
     this._validUploads = 0;
     const $uploadTarget = $(this.element);
     try {
diff --git a/app/assets/javascripts/discourse/app/mixins/upload.js b/app/assets/javascripts/discourse/app/mixins/upload.js
index 780b37536b..ff7a73be57 100644
--- a/app/assets/javascripts/discourse/app/mixins/upload.js
+++ b/app/assets/javascripts/discourse/app/mixins/upload.js
@@ -103,6 +103,10 @@ export default Mixin.create({
     });
 
     $upload.on("fileuploadprogressall", (e, data) => {
+      if (this.isDestroying || this.isDestroyed) {
+        return;
+      }
+
       const progress = parseInt((data.loaded / data.total) * 100, 10);
       this.set("uploadProgress", progress);
     });
diff --git a/app/assets/javascripts/discourse/app/mixins/uppy-upload.js b/app/assets/javascripts/discourse/app/mixins/uppy-upload.js
index 101fce1ccc..5c9cbb8aeb 100644
--- a/app/assets/javascripts/discourse/app/mixins/uppy-upload.js
+++ b/app/assets/javascripts/discourse/app/mixins/uppy-upload.js
@@ -128,6 +128,10 @@ export default Mixin.create({
     this._uppyInstance.use(UppyChecksum, { capabilities: this.capabilities });
 
     this._uppyInstance.on("progress", (progress) => {
+      if (this.isDestroying || this.isDestroyed) {
+        return;
+      }
+
       this.set("uploadProgress", progress);
     });
 
diff --git a/app/assets/javascripts/discourse/app/routes/user-activity-read.js b/app/assets/javascripts/discourse/app/routes/user-activity-read.js
index 1cfd2c9856..7622ea03ce 100644
--- a/app/assets/javascripts/discourse/app/routes/user-activity-read.js
+++ b/app/assets/javascripts/discourse/app/routes/user-activity-read.js
@@ -1,5 +1,6 @@
 import UserAction from "discourse/models/user-action";
 import UserTopicListRoute from "discourse/routes/user-topic-list";
+import { action } from "@ember/object";
 
 export default UserTopicListRoute.extend({
   userActionType: UserAction.TYPES.topics,
@@ -9,4 +10,9 @@ export default UserTopicListRoute.extend({
       filter: "read",
     });
   },
+
+  @action
+  refresh() {
+    this.refresh();
+  },
 });
diff --git a/app/assets/javascripts/discourse/app/routes/user-activity-topics.js b/app/assets/javascripts/discourse/app/routes/user-activity-topics.js
index 3e736f3514..7a08b365cf 100644
--- a/app/assets/javascripts/discourse/app/routes/user-activity-topics.js
+++ b/app/assets/javascripts/discourse/app/routes/user-activity-topics.js
@@ -1,5 +1,6 @@
 import UserAction from "discourse/models/user-action";
 import UserTopicListRoute from "discourse/routes/user-topic-list";
+import { action } from "@ember/object";
 
 export default UserTopicListRoute.extend({
   userActionType: UserAction.TYPES.topics,
@@ -10,4 +11,9 @@ export default UserTopicListRoute.extend({
         "topics/created-by/" + this.modelFor("user").get("username_lower"),
     });
   },
+
+  @action
+  refresh() {
+    this.refresh();
+  },
 });
diff --git a/app/assets/javascripts/select-kit/addon/components/select-kit/select-kit-row.js b/app/assets/javascripts/select-kit/addon/components/select-kit/select-kit-row.js
index 7eac79d9ae..cb860e66f8 100644
--- a/app/assets/javascripts/select-kit/addon/components/select-kit/select-kit-row.js
+++ b/app/assets/javascripts/select-kit/addon/components/select-kit/select-kit-row.js
@@ -158,6 +158,10 @@ export default Component.extend(UtilsMixin, {
     }
   },
 
+  focusIn(event) {
+    event.stopImmediatePropagation();
+  },
+
   keyDown(event) {
     if (this.selectKit.isExpanded) {
       if (event.key === "Backspace") {
diff --git a/app/models/topic_embed.rb b/app/models/topic_embed.rb
index 380daafb5b..2b2523aa12 100644
--- a/app/models/topic_embed.rb
+++ b/app/models/topic_embed.rb
@@ -27,10 +27,10 @@ class TopicEmbed < ActiveRecord::Base
   end
 
   # Import an article from a source (RSS/Atom/Other)
-  def self.import(user, url, title, contents, category_id: nil)
+  def self.import(user, url, title, contents, category_id: nil, cook_method: nil)
     return unless url =~ /^https?\:\/\//
 
-    if SiteSetting.embed_truncate
+    if SiteSetting.embed_truncate && cook_method.nil?
       contents = first_paragraph_from(contents)
     end
     contents ||= ''
@@ -47,7 +47,7 @@ class TopicEmbed < ActiveRecord::Base
       Topic.transaction do
         eh = EmbeddableHost.record_for_url(url)
 
-        cook_method = if SiteSetting.embed_support_markdown
+        cook_method ||= if SiteSetting.embed_support_markdown
           Post.cook_methods[:regular]
         else
           Post.cook_methods[:raw_html]
diff --git a/config/initializers/100-sidekiq.rb b/config/initializers/100-sidekiq.rb
index 9311b1633f..d4c1ddfbee 100644
--- a/config/initializers/100-sidekiq.rb
+++ b/config/initializers/100-sidekiq.rb
@@ -111,5 +111,8 @@ class SidekiqLogsterReporter < Sidekiq::ExceptionHandler::Logger
   end
 end
 
-Sidekiq.error_handlers.clear
+unless Rails.env.development?
+  Sidekiq.error_handlers.clear
+end
+
 Sidekiq.error_handlers << SidekiqLogsterReporter.new
diff --git a/lib/tasks/release_note.rake b/lib/tasks/release_note.rake
index 01bc01b35b..0b75aae522 100644
--- a/lib/tasks/release_note.rake
+++ b/lib/tasks/release_note.rake
@@ -17,7 +17,7 @@ task "release_note:generate", :from, :to, :repo do |t, args|
   changes = find_changes(repo, args[:from], args[:to])
 
   CHANGE_TYPES.each do |ct|
-    print_changes(ct[:heading], changes[ct])
+    print_changes(ct[:heading], changes[ct], "###")
   end
 
   if changes.values.all?(&:empty?)
@@ -54,11 +54,10 @@ task "release_note:plugins:generate", :from, :to, :plugin_glob, :org do |t, args
       next
     end
 
-    puts "## #{name}\n\n"
+    puts "### #{name}\n\n"
     CHANGE_TYPES.each do |ct|
-      print_changes(ct[:heading], changes[ct])
+      print_changes(ct[:heading], changes[ct], "####")
     end
-    puts "---", ""
   end
 
   puts "(No changes found in #{no_changes_repos.join(", ")})"
@@ -99,10 +98,10 @@ def find_changes(repo, from, to)
   changes
 end
 
-def print_changes(heading, changes)
+def print_changes(heading, changes, importance)
   return if changes.length == 0
 
-  puts "### #{heading}", ""
+  puts "#{importance} #{heading}", ""
   puts changes.to_a, ""
 end
 
diff --git a/lib/version.rb b/lib/version.rb
index f444aec5b0..67b960944b 100644
--- a/lib/version.rb
+++ b/lib/version.rb
@@ -10,7 +10,7 @@ module Discourse
       MAJOR = 2
       MINOR = 8
       TINY  = 0
-      PRE   = 'beta5'
+      PRE   = 'beta6'
 
       STRING = [MAJOR, MINOR, TINY, PRE].compact.join('.')
     end
diff --git a/plugins/discourse-details/assets/javascripts/initializers/apply-details.js.es6 b/plugins/discourse-details/assets/javascripts/initializers/apply-details.js.es6
index a086779131..11b2117f8f 100644
--- a/plugins/discourse-details/assets/javascripts/initializers/apply-details.js.es6
+++ b/plugins/discourse-details/assets/javascripts/initializers/apply-details.js.es6
@@ -15,6 +15,7 @@ function initializeDetails(api) {
   });
 
   api.modifyClass("controller:composer", {
+    pluginId: "discourse-details",
     actions: {
       insertDetails() {
         this.toolbarEvent.applySurround(
diff --git a/plugins/discourse-local-dates/assets/javascripts/initializers/discourse-local-dates.js.es6 b/plugins/discourse-local-dates/assets/javascripts/initializers/discourse-local-dates.js.es6
index 68b94e7aeb..30c1b5c510 100644
--- a/plugins/discourse-local-dates/assets/javascripts/initializers/discourse-local-dates.js.es6
+++ b/plugins/discourse-local-dates/assets/javascripts/initializers/discourse-local-dates.js.es6
@@ -82,6 +82,7 @@ function initializeDiscourseLocalDates(api) {
   });
 
   api.modifyClass("component:d-editor", {
+    pluginId: "discourse-local-dates",
     actions: {
       insertDiscourseLocalDate(toolbarEvent) {
         showModal("discourse-local-dates-create-modal").setProperties({
diff --git a/plugins/discourse-narrative-bot/assets/javascripts/initializers/new-user-narrative.js.es6 b/plugins/discourse-narrative-bot/assets/javascripts/initializers/new-user-narrative.js.es6
index 156c4dd0cd..89d8c460a1 100644
--- a/plugins/discourse-narrative-bot/assets/javascripts/initializers/new-user-narrative.js.es6
+++ b/plugins/discourse-narrative-bot/assets/javascripts/initializers/new-user-narrative.js.es6
@@ -1,12 +1,15 @@
 import { ajax } from "discourse/lib/ajax";
 import { withPluginApi } from "discourse/lib/plugin-api";
 
+const PLUGIN_ID = "new-user-narrative";
+
 function initialize(api) {
   const messageBus = api.container.lookup("message-bus:main");
   const currentUser = api.getCurrentUser();
   const appEvents = api.container.lookup("service:app-events");
 
   api.modifyClass("component:site-header", {
+    pluginId: PLUGIN_ID,
     didInsertElement() {
       this._super(...arguments);
       this.dispatch("header:search-context-trigger", "header");
@@ -14,6 +17,8 @@ function initialize(api) {
   });
 
   api.modifyClass("controller:topic", {
+    pluginId: PLUGIN_ID,
+
     _togglePostBookmark(post) {
       // if we are talking to discobot then any bookmarks should just
       // be created without reminder options, to streamline the new user
diff --git a/plugins/poll/assets/javascripts/initializers/add-poll-ui-builder.js.es6 b/plugins/poll/assets/javascripts/initializers/add-poll-ui-builder.js.es6
index abeb3056c6..ab5c59cfea 100644
--- a/plugins/poll/assets/javascripts/initializers/add-poll-ui-builder.js.es6
+++ b/plugins/poll/assets/javascripts/initializers/add-poll-ui-builder.js.es6
@@ -4,6 +4,7 @@ import { withPluginApi } from "discourse/lib/plugin-api";
 
 function initializePollUIBuilder(api) {
   api.modifyClass("controller:composer", {
+    pluginId: "discourse-poll-ui-builder",
     @discourseComputed(
       "siteSettings.poll_enabled",
       "siteSettings.poll_minimum_trust_level_to_create",
diff --git a/plugins/poll/assets/javascripts/initializers/extend-for-poll.js.es6 b/plugins/poll/assets/javascripts/initializers/extend-for-poll.js.es6
index 6d9505704e..ab0fb09570 100644
--- a/plugins/poll/assets/javascripts/initializers/extend-for-poll.js.es6
+++ b/plugins/poll/assets/javascripts/initializers/extend-for-poll.js.es6
@@ -4,10 +4,30 @@ import { getRegister } from "discourse-common/lib/get-owner";
 import { observes } from "discourse-common/utils/decorators";
 import { withPluginApi } from "discourse/lib/plugin-api";
 
+const PLUGIN_ID = "discourse-poll";
+let _glued = [];
+let _interval = null;
+
+function rerender() {
+  _glued.forEach((g) => g.queueRerender());
+}
+
+function cleanUpPolls() {
+  if (_interval) {
+    clearInterval(_interval);
+    _interval = null;
+  }
+
+  _glued.forEach((g) => g.cleanUp());
+  _glued = [];
+}
+
 function initializePolls(api) {
   const register = getRegister(api);
+  cleanUpPolls();
 
   api.modifyClass("controller:topic", {
+    pluginId: PLUGIN_ID,
     subscribe() {
       this._super(...arguments);
       this.messageBus.subscribe("/polls/" + this.get("model.id"), (msg) => {
@@ -23,14 +43,8 @@ function initializePolls(api) {
     },
   });
 
-  let _glued = [];
-  let _interval = null;
-
-  function rerender() {
-    _glued.forEach((g) => g.queueRerender());
-  }
-
   api.modifyClass("model:post", {
+    pluginId: PLUGIN_ID,
     _polls: null,
     pollsObject: null,
 
@@ -110,16 +124,6 @@ function initializePolls(api) {
     });
   }
 
-  function cleanUpPolls() {
-    if (_interval) {
-      clearInterval(_interval);
-      _interval = null;
-    }
-
-    _glued.forEach((g) => g.cleanUp());
-    _glued = [];
-  }
-
   api.includePostAttributes("polls", "polls_votes");
   api.decorateCooked(attachPolls, { onlyStream: true, id: "discourse-poll" });
   api.cleanupStream(cleanUpPolls);
diff --git a/spec/models/topic_embed_spec.rb b/spec/models/topic_embed_spec.rb
index decb502806..6a4e0025db 100644
--- a/spec/models/topic_embed_spec.rb
+++ b/spec/models/topic_embed_spec.rb
@@ -99,11 +99,22 @@ describe TopicEmbed do
 
       it "creates the topic in the category passed as a parameter" do
         Jobs.run_immediately!
-        SiteSetting.embed_unlisted = false
         imported_post = TopicEmbed.import(user, "http://eviltrout.com/abcd", title, "some random content", category_id: category.id)
         expect(imported_post.topic.category).not_to eq(embeddable_host.category)
         expect(imported_post.topic.category).to eq(category)
       end
+
+      it "respects overriding the cook_method when asked" do
+        Jobs.run_immediately!
+        SiteSetting.embed_support_markdown = false
+        stub_request(:get, "https://www.youtube.com/watch?v=K56soYl0U1w")
+          .to_return(status: 200, body: "", headers: {})
+        stub_request(:get, "https://www.youtube.com/embed/K56soYl0U1w")
+          .to_return(status: 200, body: "", headers: {})
+
+        imported_post = TopicEmbed.import(user, "http://eviltrout.com/abcd", title, "https://www.youtube.com/watch?v=K56soYl0U1w", cook_method: Post.cook_methods[:regular])
+        expect(imported_post.cooked).to match(/onebox|iframe/)
+      end
     end
 
     context "post creation supports markdown rendering" do