Failed Ful Publish: This request requires authentication...

Our primary full publish failed this weekend with the following error:

“This request requires authentication, but the current session is not authenticated. The user session may have expired or the server may have been restarted. You must log back into Rhythmyx to continue.”

The job ran for 11:35 hours until it stopped. I’ve not seen this before and subsequent smaller jobs ran fine. Previous weeks of this job didn’t have this error.

Any ideas?