Hi We are using Debian GNU/Linux 10 with Koha 21.11.09 (after an update from Debian 9 and Koha 19.05.02). Since the update the CAS authentication via Koha OPAC is no more working. The content of system preferences "OPACBaseURL", "casAuthentication", "casLogout" and "casServerUrl" has not changed; the new preference "casServerVersion" ist correctly set to "CAS 2 or earlier". It is possible to successfully log into the CAS server but when trying to access the Koha OPAC via CAS ("Log in using a CAS account") the response is always "Sorry, the CAS login failed." and the user is not logged into his Koha account. The logs don't show no error. I was checking all changes made in bugs 21973 22585 23771 20854 and 28417 but to no avail. Does anyone have an idea how to debug this problem? Best wishes: Michael -- Geschäftsführer · Diplombibliothekar BBS, Informatiker eidg. Fachausweis Admin Kuhn GmbH · Pappelstrasse 20 · 4123 Allschwil · Schweiz T 0041 (0)61 261 55 61 · E mik@adminkuhn.ch · W www.adminkuhn.ch