Fix One
If other jobs are running successfully, go to the Windows Task Scheduler and duplicate the "Security" options from one of the import/export jobs that are currently working to the import/export job that doesn't work.

Fix Two
Try disabling and enabling the import or export job in ADX itself. Be sure to set the "Security" options directly from the Windows Task Scheduler again.
Fix Three
Try adjusting the Scheduled Task to run at another time. For example, 5:10 AM instead of 5:00 AM. This may help if multiple jobs are running at the same time, as they may accidentally interfere with one another.
If the problem persists, message the college's Technical Contact(s) and have them submit a ticket to Accudemia's support team.