I have a crontab job running daily as a non-root user job. Unfortunately it did stop working with the following message (in /var/log/syslog):
CRON[29256]: Authentication token is no longer valid; new one required
I have not change a password for the user running this job, neither is password expired. What is causing this issue and how to fix it? - preferable without a need to change user's password every x days.
Ubuntu 14.04.1 LTS