The following modules failed while saving their changes, their state is unknown: samba

I have an old desktop running Zentyal 3. I set it up as a file sharing machine and for more than a year it worked just fine. For some odd reason, the samba module stopped saving the ACLs and Zentyal threw the following error:
Some modules reported error when saving changes. More information on the logs
in /var/log/zentyal/
The following modules failed while saving their changes, their state is
unknown: samba
On a closer look in the zentyal.log file the following message captured my eye:
Failed to save changes in module samba: Could not get ticket: could not
acquire credentials using an initial credentials context: No ENC-TS found
After searching around a bit, I found the answer on a two year old bug on Zentyal bugtracker. I just had to run the next command as root:
samba-tool user setexpiry administrator --noexpiry
It would appear that the administrator password expired.