my Discourse version is 2026.5.0-latest.1 (fbcbdc46d8)
I am seeing repeated /logs errors when loading topic posts. The error appears to come from the bundled discourse-reactions plugin while serializing the post stream.
The site reports the message as 8 copies reported.
I checked the compare range below, but it does not look like it touches the failing backend code path, so I am reporting this separately:
Error message from /logs
Message (8 copies reported)
NameError (uninitialized constant ReactionsSerializerHelpers)
app/serializers/post_stream_serializer_mixin.rb:31:in ‘PostStreamSerializerMixin#post_stream’
app/controllers/application_controller.rb:531:in ‘ApplicationController#render_json_dump’
app/controllers/topics_controller.rb:296:in ‘TopicsController#posts’
app/controllers/application_controller.rb:452:in ‘block in ApplicationController#with_resolved_locale’
app/controllers/application_controller.rb:452:in ‘ApplicationController#with_resolved_locale’
app/controllers/application_controller.rb:1103:in ‘ApplicationController#ensure_dont_cache_page’
lib/middleware/omniauth_bypass_middleware.rb:35:in ‘Middleware::OmniauthBypassMiddleware#call’
lib/middleware/crawler_hooks.rb:13:in ‘Middleware::CrawlerHooks#call’
lib/content_security_policy/middleware.rb:12:in ‘ContentSecurityPolicy::Middleware#call’
lib/middleware/anonymous_cache.rb:420:in ‘Middleware::AnonymousCache#call’
lib/middleware/csp_script_nonce_injector.rb:12:in ‘Middleware::CspScriptNonceInjector#call’
lib/middleware/track_view_session_id_injector.rb:12:in ‘Middleware::TrackViewSessionIdInjector#call’
config/initializers/008-rack-cors.rb:14:in ‘Discourse::Cors#call’
lib/middleware/default_headers.rb:13:in ‘Middleware::DefaultHeaders#call’
config/initializers/100-quiet_logger.rb:20:in ‘DiscourseRackQuietAssetsLogger#call’
config/initializers/100-silence_logger.rb:29:in ‘SilenceLogger#call’
lib/middleware/enforce_hostname.rb:23:in ‘Middleware::EnforceHostname#call’
lib/middleware/request_tracker.rb:372:in ‘Middleware::RequestTracker#call’
lib/middleware/overload_protections.rb:18:in ‘Middleware::OverloadProtections#call’
lib/middleware/processing_request.rb:14:in ‘Middleware::ProcessingRequest#call’
Backtrace from /logs
Backtrace
plugins/discourse-reactions/lib/discourse_reactions/posts_reaction_loader.rb:10:in ‘DiscourseReactions::PostsReactionLoader#posts_with_reactions’
plugins/discourse-reactions/lib/discourse_reactions/topic_view_posts_serializer_extension.rb:7:in ‘DiscourseReactions::TopicViewPostsSerializerExtension#posts’
app/serializers/post_stream_serializer_mixin.rb:31:in ‘PostStreamSerializerMixin#post_stream’
(eval at active_model_serializers-0.8.4/lib/active_model/serializer.rb:467):3:in ‘TopicViewPostsSerializer#_fast_attributes’
active_model_serializers (0.8.4) lib/active_model/serializer.rb:468:in ‘ActiveModel::Serializer#attributes’
active_model_serializers (0.8.4) lib/active_model/serializer.rb:480:in ‘ActiveModel::Serializer#_serializable_hash’
active_model_serializers (0.8.4) lib/active_model/serializer.rb:359:in ‘ActiveModel::Serializer#serializable_hash’
active_model_serializers (0.8.4) lib/active_model/serializer.rb:347:in ‘ActiveModel::Serializer#as_json’
activesupport (8.0.5) lib/active_support/json/encoding.rb:41:in ‘Oj::Rails::Encoder#encode’
activesupport (8.0.5) lib/active_support/json/encoding.rb:41:in ‘ActiveSupport::JSON.encode’
activesupport (8.0.5) lib/active_support/core_ext/object/json.rb:42:in ‘ActiveSupport::ToJsonWithActiveSupportEncoder#to_json’
active_model_serializers (0.8.4) lib/active_model/serializer.rb:331:in ‘ActiveModel::Serializer#to_json’
multi_json (1.20.1) lib/multi_json/adapters/oj.rb:67:in ‘Oj.dump’
multi_json (1.20.1) lib/multi_json/adapters/oj.rb:67:in ‘MultiJson::Adapters::Oj#dump’
multi_json (1.20.1) lib/multi_json/adapter.rb:92:in ‘MultiJson::Adapter.dump’
multi_json (1.20.1) lib/multi_json.rb:214:in ‘MultiJson.dump’
app/controllers/application_controller.rb:531:in ‘ApplicationController#render_json_dump’
app/controllers/topics_controller.rb:296:in ‘TopicsController#posts’
actionpack (8.0.5) lib/action_controller/metal/basic_implicit_render.rb:8:in ‘ActionController::BasicImplicitRender#send_action’
actionpack (8.0.5) lib/abstract_controller/base.rb:215:in ‘AbstractController::Base#process_action’
actionpack (8.0.5) lib/action_controller/metal/rendering.rb:193:in ‘ActionController::Rendering#process_action’
actionpack (8.0.5) lib/abstract_controller/callbacks.rb:261:in ‘block in AbstractController::Callbacks#process_action’
activesupport (8.0.5) lib/active_support/callbacks.rb:120:in ‘block in ActiveSupport::Callbacks#run_callbacks’
app/controllers/application_controller.rb:452:in ‘block in ApplicationController#with_resolved_locale’
i18n (1.14.8) lib/i18n.rb:354:in ‘I18n::Base#with_locale’
app/controllers/application_controller.rb:452:in ‘ApplicationController#with_resolved_locale’
activesupport (8.0.5) lib/active_support/callbacks.rb:129:in ‘block in ActiveSupport::Callbacks#run_callbacks’
app/controllers/application_controller.rb:1103:in ‘ApplicationController#ensure_dont_cache_page’
activesupport (8.0.5) lib/active_support/callbacks.rb:129:in ‘block in ActiveSupport::Callbacks#run_callbacks’
activesupport (8.0.5) lib/active_support/callbacks.rb:140:in ‘ActiveSupport::Callbacks#run_callbacks’
actionpack (8.0.5) lib/abstract_controller/callbacks.rb:260:in ‘AbstractController::Callbacks#process_action’
actionpack (8.0.5) lib/action_controller/metal/rescue.rb:27:in ‘ActionController::Rescue#process_action’
actionpack (8.0.5) lib/action_controller/metal/instrumentation.rb:76:in ‘block in ActionController::Instrumentation#process_action’
activesupport (8.0.5) lib/active_support/notifications.rb:210:in ‘block in ActiveSupport::Notifications.instrument’
activesupport (8.0.5) lib/active_support/notifications/instrumenter.rb:58:in ‘ActiveSupport::Notifications::Instrumenter#instrument’
activesupport (8.0.5) lib/active_support/notifications.rb:210:in ‘ActiveSupport::Notifications.instrument’
actionpack (8.0.5) lib/action_controller/metal/instrumentation.rb:75:in ‘ActionController::Instrumentation#process_action’
actionpack (8.0.5) lib/action_controller/metal/params_wrapper.rb:259:in ‘ActionController::ParamsWrapper#process_action’
activerecord (8.0.5) lib/active_record/railties/controller_runtime.rb:39:in ‘ActiveRecord::Railties::ControllerRuntime#process_action’
actionpack (8.0.5) lib/abstract_controller/base.rb:152:in ‘AbstractController::Base#process’
actionview (8.0.5) lib/action_view/rendering.rb:40:in ‘ActionView::Rendering#process’
rack-mini-profiler (4.0.1) lib/mini_profiler/profiling_methods.rb:90:in ‘block in ActionController::Base#profile_method’
actionpack (8.0.5) lib/action_controller/metal.rb:252:in ‘ActionController::Metal#dispatch’
actionpack (8.0.5) lib/action_controller/metal.rb:335:in ‘ActionController::Metal.dispatch’
actionpack (8.0.5) lib/action_dispatch/routing/route_set.rb:67:in ‘ActionDispatch::Routing::RouteSet::Dispatcher#dispatch’
actionpack (8.0.5) lib/action_dispatch/routing/route_set.rb:50:in ‘ActionDispatch::Routing::RouteSet::Dispatcher#serve’
actionpack (8.0.5) lib/action_dispatch/journey/router.rb:53:in ‘block in ActionDispatch::Journey::Router#serve’
actionpack (8.0.5) lib/action_dispatch/journey/router.rb:133:in ‘block in ActionDispatch::Journey::Router#find_routes’
actionpack (8.0.5) lib/action_dispatch/journey/router.rb:126:in ‘Array#each’
actionpack (8.0.5) lib/action_dispatch/journey/router.rb:126:in ‘ActionDispatch::Journey::Router#find_routes’
actionpack (8.0.5) lib/action_dispatch/journey/router.rb:34:in ‘ActionDispatch::Journey::Router#serve’
actionpack (8.0.5) lib/action_dispatch/routing/route_set.rb:908:in ‘ActionDispatch::Routing::RouteSet#call’
lib/middleware/omniauth_bypass_middleware.rb:35:in ‘Middleware::OmniauthBypassMiddleware#call’
lib/middleware/crawler_hooks.rb:13:in ‘Middleware::CrawlerHooks#call’
rack (2.2.23) lib/rack/tempfile_reaper.rb:15:in ‘Rack::TempfileReaper#call’
rack (2.2.23) lib/rack/conditional_get.rb:27:in ‘Rack::ConditionalGet#call’
rack (2.2.23) lib/rack/head.rb:12:in ‘Rack::Head#call’
actionpack (8.0.5) lib/action_dispatch/http/permissions_policy.rb:38:in ‘ActionDispatch::PermissionsPolicy::Middleware#call’
lib/content_security_policy/middleware.rb:12:in ‘ContentSecurityPolicy::Middleware#call’
lib/middleware/anonymous_cache.rb:420:in ‘Middleware::AnonymousCache#call’
lib/middleware/csp_script_nonce_injector.rb:12:in ‘Middleware::CspScriptNonceInjector#call’
lib/middleware/track_view_session_id_injector.rb:12:in ‘Middleware::TrackViewSessionIdInjector#call’
config/initializers/008-rack-cors.rb:14:in ‘Discourse::Cors#call’
rack (2.2.23) lib/rack/session/abstract/id.rb:266:in ‘Rack::Session::Abstract::Persisted#context’
rack (2.2.23) lib/rack/session/abstract/id.rb:260:in ‘Rack::Session::Abstract::Persisted#call’
actionpack (8.0.5) lib/action_dispatch/middleware/cookies.rb:706:in ‘ActionDispatch::Cookies#call’
actionpack (8.0.5) lib/action_dispatch/middleware/callbacks.rb:31:in ‘block in ActionDispatch::Callbacks#call’
activesupport (8.0.5) lib/active_support/callbacks.rb:100:in ‘ActiveSupport::Callbacks#run_callbacks’
actionpack (8.0.5) lib/action_dispatch/middleware/callbacks.rb:30:in ‘ActionDispatch::Callbacks#call’
actionpack (8.0.5) lib/action_dispatch/middleware/debug_exceptions.rb:31:in ‘ActionDispatch::DebugExceptions#call’
actionpack (8.0.5) lib/action_dispatch/middleware/show_exceptions.rb:32:in ‘ActionDispatch::ShowExceptions#call’
logster (2.21.0) lib/logster/middleware/reporter.rb:40:in ‘Logster::Middleware::Reporter#call’
lib/middleware/default_headers.rb:13:in ‘Middleware::DefaultHeaders#call’
railties (8.0.5) lib/rails/rack/logger.rb:41:in ‘Rails::Rack::Logger#call_app’
railties (8.0.5) lib/rails/rack/logger.rb:29:in ‘Rails::Rack::Logger#call’
config/initializers/100-quiet_logger.rb:20:in ‘DiscourseRackQuietAssetsLogger#call’
config/initializers/100-silence_logger.rb:29:in ‘SilenceLogger#call’
actionpack (8.0.5) lib/action_dispatch/middleware/request_id.rb:34:in ‘ActionDispatch::RequestId#call’
lib/middleware/enforce_hostname.rb:23:in ‘Middleware::EnforceHostname#call’
rack (2.2.23) lib/rack/method_overrid
What appears to be happening
The error occurs when TopicsController#posts renders JSON for the post stream.
The backtrace points into:
plugins/discourse-reactions/lib/discourse_reactions/posts_reaction_loader.rb
and then into:
plugins/discourse-reactions/lib/discourse_reactions/topic_view_posts_serializer_extension.rb
The failing constant appears to be:
ReactionsSerializerHelpers
So this looks like either:
ReactionsSerializerHelpersis not being loaded/defined beforePostsReactionLoaderreferences it, or- a stale/mixed plugin/core state is causing the bundled reactions plugin to reference a helper that is not present in the running code.
Question
Is this expected to be fixed by a later commit, or is this a load-order / bundled-plugin issue in reactions?
I am happy to provide further environment details if useful.