After one of the cron jobs experienced an error, the other scheduled cron jobs are not starting on their own when their scheduled time occurs.
An example is the mail_queue cron. It is supposed to run every minute. I can run it manually and it will send mail, but the master cron job isn't picking it up after for the recurring execution times.
The master cron job in the windows task scheduler was running with the IIS_IUSR account.
Changed the master cron job in the Windows Task scheduler to run with a service account.
The user that runs the master cron job should have permission to the SAM database.