# An unexpected authentication error occurred. Please log in again. **URL:** \ **Category:** Kibana\ **Created:** [April 30, 2025, 2:42pm UTC](https://discuss.elastic.co/t/an-unexpected-authentication-error-occurred-please-log-in-again/377678 "2025-04-30T14:42:06Z")\ **Posts on this page:** 9\ **Page:** 1
**Author:** ![GiorgioS13](https://avatars.discourse-cdn.com/v4/letter/g/5fc32e/32.png) [@GiorgioS13](https://discuss.elastic.co/u/GiorgioS13)\ **Post date:** [April 30, 2025, 2:42pm UTC](https://discuss.elastic.co/t/an-unexpected-authentication-error-occurred-please-log-in-again/377678/1 "2025-04-30T14:42:06Z")
Hello, Yesterday we upgraded from version 8.18 to 9.0 without any issues, and I didn’t change any configurations. However, today I’m receiving this error when trying to perform actions in Kibana. Does anyone have an idea what might be causing this issue and how it could be resolved? ---
**Author:** ![GiorgioS13](https://avatars.discourse-cdn.com/v4/letter/g/5fc32e/32.png) [@GiorgioS13](https://discuss.elastic.co/u/GiorgioS13)\ **Post date:** [May 1, 2025, 8:00am UTC](https://discuss.elastic.co/t/an-unexpected-authentication-error-occurred-please-log-in-again/377678/2 "2025-05-01T08:00:56Z")
![1](https://us1.discourse-cdn.com/elastic/original/3X/1/3/1392154033fa6d6a4d99e41339ea1a1b084c2a82.png) ---
**Author:** ![Rios](https://sea2.discourse-cdn.com/elastic/user_avatar/discuss.elastic.co/rios/32/95745_2.png) [@Rios](https://discuss.elastic.co/u/Rios)\ **Post date:** [May 1, 2025, 8:54am UTC](https://discuss.elastic.co/t/an-unexpected-authentication-error-occurred-please-log-in-again/377678/3 "2025-05-01T08:54:14Z")
Welcome to the community. Check kibana.log, some info should be there. ---
**Author:** ![engineerwithahat](https://avatars.discourse-cdn.com/v4/letter/e/e8c25b/32.png) [@engineerwithahat](https://discuss.elastic.co/u/engineerwithahat)\ **Post date:** [May 6, 2025, 1:41pm UTC](https://discuss.elastic.co/t/an-unexpected-authentication-error-occurred-please-log-in-again/377678/4 "2025-05-06T13:41:06Z")
What browser are you using to access Kibana? We had similar issues after we upgraded Firefox to newest version 138.01. ---
**Author:** ![UweW](https://avatars.discourse-cdn.com/v4/letter/u/ed8c4c/32.png) [@UweW](https://discuss.elastic.co/u/UweW)\ **Post date:** [May 7, 2025, 12:23pm UTC](https://discuss.elastic.co/t/an-unexpected-authentication-error-occurred-please-log-in-again/377678/5 "2025-05-07T12:23:39Z")
I have the same issue after updating 2 diffrent environments to 9.0. But I have the probelm only in combination with firefox. ---
**Author:** ![edgebg](https://avatars.discourse-cdn.com/v4/letter/e/5fc32e/32.png) [@edgebg](https://discuss.elastic.co/u/edgebg)\ **Post date:** [May 7, 2025, 6:19pm UTC](https://discuss.elastic.co/t/an-unexpected-authentication-error-occurred-please-log-in-again/377678/6 "2025-05-07T18:19:27Z")
I am also seeing this issue with Firefox 138.0.1 and Kibana version 8.14.3. ---
**Author:** ![natharran](https://avatars.discourse-cdn.com/v4/letter/n/7feea3/32.png) [@natharran](https://discuss.elastic.co/u/natharran)\ **Post date:** [May 9, 2025, 4:50pm UTC](https://discuss.elastic.co/t/an-unexpected-authentication-error-occurred-please-log-in-again/377678/7 "2025-05-09T16:50:58Z")
I'm also experiencing this issue after upgrade to 9.0.0 with Firefox 138.0.1. ---
**Author:** ![stephenb](https://sea2.discourse-cdn.com/elastic/user_avatar/discuss.elastic.co/stephenb/32/40856_2.png) [@stephenb](https://discuss.elastic.co/u/stephenb)\ **Post date:** [May 9, 2025, 5:58pm UTC](https://discuss.elastic.co/t/an-unexpected-authentication-error-occurred-please-log-in-again/377678/8 "2025-05-09T17:58:10Z")
Hi Folks I pinged internally... we will see what comes back... lets keep it in this thread ---
**Author:** ![Larry\_Gregory](https://sea2.discourse-cdn.com/elastic/user_avatar/discuss.elastic.co/larry_gregory/32/34969_2.png) [@Larry\_Gregory](https://discuss.elastic.co/u/Larry_Gregory)\ **Post date:** [May 9, 2025, 6:21pm UTC](https://discuss.elastic.co/t/an-unexpected-authentication-error-occurred-please-log-in-again/377678/9 "2025-05-09T18:21:30Z")
Hey folks, We've identified the issue as a regression in Firefox which does not play nicely with the way Kibana manages its session cookie. We have a fix in progress on the Kibana side to workaround the problem, and we've filed a bug report with Mozilla as well: - [Unexpected logouts from Kibana dashboards in Firefox · Issue #220637 · elastic/kibana · GitHub](https://github.com/elastic/kibana/issues/220637) - [1965056 - Cache re-validation request includes duplicated cookies](https://bugzilla.mozilla.org/show_bug.cgi?id=1965056)