Only solution I found is to use Buddypress. When u install Buddypress u can choose which part to use. Check only Private Messaging and Forum. thats it. Now you’ll have your old forum and new function PM.
PM button is not in the post, you need to click on the username first, but it’s probably not so difficult to integrate it in the posts.
https://wordpress.org/extend/plugins/bbpress-private-replies/
Only private replays to public topics. (can be seen by topic creator, moderators and user who post it)
Im also looking for private messaging plugin for bbpress.
Or private topics – same as private replays, but for whole topic.
