The master cron job in the windows task scheduler was configured to use the IIS_IUSR. The option 'run whether user is logged in or not' was greyed out and we could not set this option.
Steps to resolve:
1. Configured the task to run with the local administrator account (or any other account that has permissions to the SAM directories)
2. Set this task to 'Run whether user is logged in or not'
3. If the next run date on the cron job is set to run at a past date, then edit each cron job and change the next run date to a future date.