在我升级/重新构建不到一小时后，访问 /g 组索引页面时看到了标题中显示的消息。
作为管理员，我也无法访问各个组页面（在无痕模式下未登录时它们工作正常）。我收到以下错误：
服务器错误
尝试加载 [/groups/CTRG.json](https://domain.com/groups/CTRG.json) 时出错
错误代码：500 错误
日志中显示以下内容：
NoMethodError（字符串 "category-theory" 没有 `notification_level` 方法）
app/serializers/basic_group_serializer.rb:152:in `block (3 levels) in <class:BasicGroupSerializer>'
app/serializers/basic_group_serializer.rb:151:in `filter'
app/serializers/basic_group_serializer.rb:151:in `block (2 levels) in <class:BasicGroupSerializer>'
(eval):53:in `_fast_attributes'
app/controllers/application_controller.rb:438:in `serialize_data'
app/controllers/groups_controller.rb:93:in `index'
app/controllers/application_controller.rb:340:in `block in with_resolved_locale'
app/controllers/application_controller.rb:340:in `with_resolved_locale'
lib/middleware/omniauth_bypass_middleware.rb:68:in `call'
lib/content_security_policy/middleware.rb:12:in `call'
lib/middleware/anonymous_cache.rb:336:in `call'
config/initializers/100-quiet_logger.rb:23:in `call'
config/initializers/100-silence_logger.rb:31:in `call'
lib/middleware/enforce_hostname.rb:22:in `call'
lib/middleware/request_tracker.rb:176:in `call'
其中 category-theory 是一个标签的名称。我几天前曾为该标签设置了组级别的通知。
这可能是由于最近对 PERF: Use 1 query to load group and tag notification default. · discourse/discourse@5ef9d4d · GitHub 的更改所致，cc: @tgxworld