I was able to reproduce this error in activeadmin while using searching/filtering over text field(filter :question, filters: [:cont])
undefined method `table_name' for #<Arel::Table:0x00007efe88977f38 @name="cards", @klass=Card(id: integer, deck_id: integer, question: text, created_at: datetime, updated_at: datetime), @type_caster=#<ActiveRecord::TypeCaster::Map:0x00007efe88977df8 @klass=Card(id: integer, deck_id: integer, question: text, created_at: datetime, updated_at: datetime)>, @table_alias=nil>
What's causing it and how to fix it?
ransack: 4.0.0
activeadmin(3-0-stable)