[deleted] did you previously deleted some tables manually ? Extensions use migrations to keep the database in sync. If you deleted tables but not the corresponding entries in the migrations table, then the extension can't know that it needs to re-create them.
The only safe way to remove an extension's table or column is to rollback migrations. This can be achieved by selecting "uninstall" on the extensions page, uninstalling via Bazaar or manually running the php flarum migrate:reset --extension=vendor-package extension. Sadly if any error occurs during one of those actions, the database might be left in a state requiring manual repair.
