We have been using Koha for about 1-1/2 years now but we don’ consider ourselves Koha experts. I upgraded our Koha development environment system from 23.05.11 to 24.05.00 last week. It is running in an Ubuntu 22.04.4 LTS (5.15.0-112-generic #122-Ubuntu SMP) in an AMD virtual machine. The system has a 40G disk with 15G available. It has a duplicate of our Koha production install. After enabling the ERM module and adding a couple of test licenses, etc. The next time I attempted to login to the staff interface I got an Error 303 “The form submission failed (Wrong CSRF token). Try to come back, refresh the page, then try again.” I have cleared the cache browser (on all browsers), rebooted the system - no change. If I login using the OPAC interface and then open a new window to the staff interface, without quiting the browser, it succeeds since I don’t have to login. All of this behavior occurs regardless of the whether I use Firefox, Chrome, or Safari. The Apache and Koha logs do not show any problem. I am an experienced Linux system administrator and developer. I can read and write PERL but don’t consider myself a PERL expert. Is there a way to turn on more logging, specific things to try? Any assistance would be greatly appreciated.