bbPress.org

I am on WordPress 4.7.2 and bbPress 2.5.12 and suddenly this combination stopped working layoutwise. bbPress is just outputting content (text), but without any tables or any other formatting.

The glitch happens with all WordPress themes not just a particular theme.
I am using “bbPress Tweaks” to render the output in my theme. Deactivating bbPress Tweaks did not solve it.

Unfortunately we use this website for internal communications, so can’t just put a link here, you have to have an active user to login.

Therefore I uploaded some pictures of what is happening:
https://www.rainbow-international.de/screen.jpg
https://www.rainbow-international.de/screen2.jpg

I tried everything disabling plugins, downgrading WordPress, downgrading bbPress itself. But I can’t get the older versions of bbPress to run. Something in the code is crashing -> white page. So I am stuck with 2.5.12.

Thank you in advance!