Hi,

On a Rails 6 rc2 project, when attempting to access forum index, I'm encountering the following error :

PG::UndefinedTable: ERROR: missing FROM-clause entry for table "thredded_topics"

The generated SQL is:

"SELECT "thredded_messageboards".* FROM "thredded_messageboards" LEFT OUTER JOIN "thredded_user_topic_read_states" ON "thredded_messageboards"."id" = "thredded_user_topic_read_states"."messageboard_id" AND "thredded_user_topic_read_states"."postable_id" = "thredded_topics"."id" AND "thredded_user_topic_read_states"."user_id" IS NULL AND "thredded_user_topic_read_states"."unread_posts_count" = 0 INNER JOIN "thredded_topics" ON "thredded_topics"."messageboard_id" = "thredded_messageboards"."id" WHERE ("thredded_topics"."moderation_state" != 2 OR "thredded_topics"."user_id" IS NULL) GROUP BY "thredded_messageboards"."id""

I tried to find a solution but quickly got lost with all those arel tables in this class method