大家好，Discourse 社区！
我们使用 Docker 在 Debian 虚拟机上运行 Discourse 2.4.5 版本。当尝试以已登录用户（在我的情况下是管理员）身份访问某些页面时，Discourse 日志中会出现以下错误信息：
NoMethodError (undefined method
automatic_membership_retroactive' for #<Group:0x00007fb84804bac0>) /var/www/discourse/vendor/bundle/ruby/2.6.0/gems/activemodel-6.0.1/lib/active_model/attribute_methods.rb:431:inmethod_missing’
受影响的页面包括：
问题不仅出现在我自己的个人资料页面（/u/mathieugp）上，所有用户的个人资料页面都会导致 Discourse 错误日志报错，并在客户端显示 500 错误。有时在加载某些其他页面（据我判断是子页面）时，错误日志会显示 404 错误，例如：
- /u/mathieugp/summary
未登录时，我可以查看自己的个人资料（以及其他用户的资料）。显然，未登录时我无法查看任何有用的群组管理内容，但此时也不会显示任何异常错误。
以下是 Discourse 日志中的完整堆栈跟踪：
> activemodel-6.0.1/lib/active_model/attribute_methods.rb:431:in `method_missing'
> active_model_serializers-0.8.4/lib/active_model/serializer.rb:99:in `block in attribute'
> (eval):12:in `_fast_attributes'
> active_model_serializers-0.8.4/lib/active_model/serializer.rb:468:in `rescue in attributes'
> active_model_serializers-0.8.4/lib/active_model/serializer.rb:455:in `attributes'
> active_model_serializers-0.8.4/lib/active_model/serializer.rb:480:in `_serializable_hash'
> active_model_serializers-0.8.4/lib/active_model/serializer.rb:359:in `serializable_hash'
> active_model_serializers-0.8.4/lib/active_model/array_serializer.rb:89:in `block in _serializable_array'
> active_model_serializers-0.8.4/lib/active_model/array_serializer.rb:79:in `map'
> active_model_serializers-0.8.4/lib/active_model/array_serializer.rb:79:in `_serializable_array'
> active_model_serializers-0.8.4/lib/active_model/array_serializer.rb:73:in `serializable_array'
> active_model_serializers-0.8.4/lib/active_model/array_serializer.rb:53:in `as_json'
> /var/www/discourse/app/controllers/application_controller.rb:427:in `serialize_data'
> /var/www/discourse/app/controllers/groups_controller.rb:91:in `index'
> actionpack-6.0.1/lib/action_controller/metal/basic_implicit_render.rb:6:in `send_action'
> actionpack-6.0.1/lib/abstract_controller/base.rb:196:in `process_action'
> actionpack-6.0.1/lib/action_controller/metal/rendering.rb:30:in `process_action'
> actionpack-6.0.1/lib/abstract_controller/callbacks.rb:42:in `block in process_action'
> activesupport-6.0.1/lib/active_support/callbacks.rb:135:in `run_callbacks'
> actionpack-6.0.1/lib/abstract_controller/callbacks.rb:41:in `process_action'
> actionpack-6.0.1/lib/action_controller/metal/rescue.rb:22:in `process_action'
> actionpack-6.0.1/lib/action_controller/metal/instrumentation.rb:33:in `block in process_action'
> activesupport-6.0.1/lib/active_support/notifications.rb:180:in `block in instrument'
> activesupport-6.0.1/lib/active_support/notifications/instrumenter.rb:24:in `instrument'
> activesupport-6.0.1/lib/active_support/notifications.rb:180:in `instrument'
> actionpack-6.0.1/lib/action_controller/metal/instrumentation.rb:32:in `process_action'
> actionpack-6.0.1/lib/action_controller/metal/params_wrapper.rb:245:in `process_action'
> activerecord-6.0.1/lib/active_record/railties/controller_runtime.rb:27:in `process_action'
> actionpack-6.0.1/lib/abstract_controller/base.rb:136:in `process'
> actionview-6.0.1/lib/action_view/rendering.rb:39:in `process'
> rack-mini-profiler-1.1.6/lib/mini_profiler/profiling_methods.rb:78:in `block in profile_method'
> actionpack-6.0.1/lib/action_controller/metal.rb:191:in `dispatch'
> actionpack-6.0.1/lib/action_controller/metal.rb:252:in `dispatch'
> actionpack-6.0.1/lib/action_dispatch/routing/route_set.rb:51:in `dispatch'
> actionpack-6.0.1/lib/action_dispatch/routing/route_set.rb:33:in `serve'
> actionpack-6.0.1/lib/action_dispatch/journey/router.rb:49:in `block in serve'
> actionpack-6.0.1/lib/action_dispatch/journey/router.rb:32:in `each'
> actionpack-6.0.1/lib/action_dispatch/journey/router.rb:32:in `serve'
> actionpack-6.0.1/lib/action_dispatch/routing/route_set.rb:837:in `call'
> /var/www/discourse/lib/middleware/omniauth_bypass_middleware.rb:68:in `call'
> rack-2.0.8/lib/rack/tempfile_reaper.rb:15:in `call'
> rack-2.0.8/lib/rack/conditional_get.rb:25:in `call'
> rack-2.0.8/lib/rack/head.rb:12:in `call'
> /var/www/discourse/lib/content_security_policy/middleware.rb:12:in `call'
> /var/www/discourse/lib/middleware/anonymous_cache.rb:318:in `call'
> rack-2.0.8/lib/rack/session/abstract/id.rb:259:in `context'
> rack-2.0.8/lib/rack/session/abstract/id.rb:253:in `call'
> actionpack-6.0.1/lib/action_dispatch/middleware/cookies.rb:648:in `call'
> actionpack-6.0.1/lib/action_dispatch/middleware/callbacks.rb:27:in `block in call'
> activesupport-6.0.1/lib/active_support/callbacks.rb:101:in `run_callbacks'
> actionpack-6.0.1/lib/action_dispatch/middleware/callbacks.rb:26:in `call'
> actionpack-6.0.1/lib/action_dispatch/middleware/actionable_exceptions.rb:17:in `call'
> actionpack-6.0.1/lib/action_dispatch/middleware/debug_exceptions.rb:32:in `call'
> actionpack-6.0.1/lib/action_dispatch/middleware/show_exceptions.rb:33:in `call'
> logster-2.6.3/lib/logster/middleware/reporter.rb:43:in `call'
> railties-6.0.1/lib/rails/rack/logger.rb:38:in `call_app'
> railties-6.0.1/lib/rails/rack/logger.rb:28:in `call'
> /var/www/discourse/config/initializers/100-quiet_logger.rb:18:in `call'
> /var/www/discourse/config/initializers/100-silence_logger.rb:31:in `call'
> actionpack-6.0.1/lib/action_dispatch/middleware/remote_ip.rb:81:in `call'
> actionpack-6.0.1/lib/action_dispatch/middleware/request_id.rb:27:in `call'
> /var/www/discourse/lib/middleware/enforce_hostname.rb:17:in `call'
> rack-2.0.8/lib/rack/method_override.rb:22:in `call'
> actionpack-6.0.1/lib/action_dispatch/middleware/executor.rb:14:in `call'
> rack-2.0.8/lib/rack/sendfile.rb:111:in `call'
> actionpack-6.0.1/lib/action_dispatch/middleware/host_authorization.rb:77:in `call'
> rack-mini-profiler-1.1.6/lib/mini_profiler/profiler.rb:184:in `call'
> message_bus-2.2.3/lib/message_bus/rack/middleware.rb:57:in `call'
> /var/www/discourse/lib/middleware/request_tracker.rb:181:in `call'
> railties-6.0.1/lib/rails/engine.rb:526:in `call'
> railties-6.0.1/lib/rails/railtie.rb:190:in `public_send'
> railties-6.0.1/lib/rails/railtie.rb:190:in `method_missing'
> rack-2.0.8/lib/rack/urlmap.rb:68:in `block in call'
> rack-2.0.8/lib/rack/urlmap.rb:53:in `each'
> rack-2.0.8/lib/rack/urlmap.rb:53:in `call'
> unicorn-5.5.3/lib/unicorn/http_server.rb:605:in `process_client'
> unicorn-5.5.3/lib/unicorn/http_server.rb:700:in `worker_loop'
> unicorn-5.5.3/lib/unicorn/http_server.rb:548:in `spawn_missing_workers'
> unicorn-5.5.3/lib/unicorn/http_server.rb:144:in `start'
> unicorn-5.5.3/bin/unicorn:128:in `<top (required)>'
> /var/www/discourse/vendor/bundle/ruby/2.6.0/bin/unicorn:23:in `load'
> /var/www/discourse/vendor/bundle/ruby/2.6.0/bin/unicorn:23:in `<main>'
请告诉我还需要提供哪些信息，以便更好地排查此问题。
我可能还应该提一下我们之前在本机 Discourse 实例上遇到的一些访问特定页面的问题。有一段时间，我甚至完全无法访问管理区域。在执行以下命令后，该问题似乎完全消失了：
# ./launcher rebuild app
之后我可以再次访问管理区域，但我未能察觉自己无法管理群组。直到几周后，当我需要向群组添加用户时，才发现了这个问题。至于查看个人资料，我不太确定：按理说我应该不可能错过如此明显的问题，但也许我当时并未登录，误以为一切正常？或者显示个人资料的问题当时并不存在，而是后来才出现的？（抱歉，以上陈述有些模糊：我确实无法完全回忆清楚，而且也没有任何线索可供追溯！）
