SOLVED, at least somewhat. Please see my next ticket for more details.
Just now my second website crashed because of the collaboration plugin. I was able to fix this one. The one yesterday is still messed up. I now deactivated all websites on which I use it.
Is that a known problem?
I didn’t make a screenshot of the error message, but if this is a common problem, please let me know how to fix it. The website which is still messed up is https://www.oksaadi.com/. Strangely enough, the website renders ok when I’m logged in. But for anyone who isn’t logged in, it’s not being rendered normally. Please advise