1. Are you sure the cron message is related to your job? I see no direct relationship between the posted crontab and the log. Be sure by checking the timestamp of the log and your actual crontab.
2. Is display :0.0 running/assigned at the time of the job execution?
3. I'd check also the scripts in /etc/cron.d, /etc/cron.hourly, /etc/cron.daily etc. to see if one of them is faulty due to the recent upgrade. For example, someone reported that /etc/cron.d/update-motd no longer works, since its functionality has been integrated into pam_motd module.