Buddypress Forum Error


I have just noticed that I am having a problem when creating new topics in Group forums. I am getting this error: There was an error when creating the topic

I added multi-databases a long time ago, and I think I may not have created a group since. Would this change the settings for the forums?

I tried changing the database in bb-config.php by adding in _global, but it didn't work.

I can still add topics to groups created before this addition.