Scheduled Robocopy task fails with 0x10 error
Solution 1:
Instead of using a mapped drive letter, use the UNC path of the share (\\servername\sharename\folder). That'll simplify things since your mapped drives are associated with your session, not necessarily the session that the scheduled task runs in.
Next, ensure that the user associated with the scheduled task has access to that share.
That should get you fixed up.