Cannot add any forum

[passegua]

I am trying to add a new category, save it.
It says: “category added”
but I don’t see any category!
Then I try also to add a forum, but I cannot!

What am I doing wrong?
Here’s my forum page:

https://lnx.sinapsi.org/wordpress/forum/domande/

Please help!

https://www.ads-software.com/extend/plugins/mingle-forum/

[cartpauj]

We got this working finally by installing WP Forum – or Forum Server, then going back to Mingle Forum for anyone else who may see this problem.