I get this error since a few days. No dashboards edits or updated plugins etc have been done.

I runt the latest version of IPB.

Have tried to clear caches and disabled my (few) addons etc, but the problem is still there.

Please help!

Your core sessions table in your MySQL database is crashed. You need to repair it.  You can attempt to fix it by using a program like phpMyAdmin to do it or if you are not comfortable doing so, you would need to contact your hosting provider for assistance. 

Edited October 25, 20231 yr by Randy Calvert

I see , many thanks!