Hi Julie!
I'm pretty sure it's a security issue on the specific drive's root.
Check for which drive this error is reported.
Is you scheduler using the SYSTEM account? Than is most likely that the
SYSTEM account has no access on the drive's root. So, if it's drive c: that
can't be backed up, check the security settings on c: and give the SYSTEM
account full control access.
Kindest regards,
Eric van Loon
KLM Royal Dutch Airlines