Do you have a file named advanced-cache.php in wp-content ? If you do, either rename it, or delete it.
I found the file, deleted, but it did not help.
I took a little step forward.
1) in wp foro admin I delete user cache;
2) Ctrl + F5;
3) everything seems ok;
4) if I only move in wpforo (my account, members, recent posts, topics), everything is ok.
5) As soon as I go to another site page, outside wpforo and then go back to wpforo, the text editor is blown.
I also noticed that the highlighting of read posts for unregistered users does not work correctly.
I'm already unhappy with it. I would need a professional to look at it and give it up.
Ok, problem solved. But i am still not happy.
I disconnected all the cache in the wpForo administration and it's all right.
But this can be a problem for load speeds not? I thought these caches should work ok?
Please make sure wpForo HTML cache is disabled in Dashboard > Forums > Settings > Features admin page. Other caches should be enabled.