unable to restore individual inbox folder - restore error

 I have a user   who accidentally deleted A SUBFOLDER in his inbox.  We tried to RECOVER (i DON'T KNOW WHY some of these words are being capitalized) the folder from the deleted items MENU but exchange could not restore THE FOLDER.  i HAVE A TAPE FROM SEVERAL WEEKS AGO WHICH lists the folder AS HAVING BEEN BACKED UP.  hOWEVER I get the following error WHEN TRYING TO RESTORE the folder to its original location:

 

Final error: 0xe000848c - Unable to attach to a resource.  Make sure that all selected resources exist and are online, and then try again.
Final error category: Resource Errors

 

 i CHECKED THE error ON THE WEB SITE and did not find RELEVANT ARTICLES.

 I am logged on as ADMINISTRATOR which is also the account USED TO BACK UP THE INDIVIDUAL MAILBOXES although there is a different account FOR GENERAL BACKUP PURPOSES.  fOR SOME REASON that accounts can't  BACKUP INDIVIDUAL MAILBOXES but that is a separate issue-I need to  BE ABLE to restore this one inbox folder.

 

tHANK YOU IN ADVANCE FOR YOUR THOUGHTS.