Backups of Virtual Machine fail with” Final error: 0xa000964c - Backup Exec was unable to open an existing VHD because the VHD may be corrupted or because you may not have logged on as an administrator”
Browsing the Hyper-v Backup Selections may show the same error.
Final error: 0xa000964c - Backup Exec was unable to open an existing VHD because the VHD may be corrupted or because you may not have logged on as an administrator.
 - bevs::IVhdFileUtil: pen_VHD: Failed to open file 'D:\<VMNAME Folder>\<VMNAME>.vhd', error: 32
 [fsys\vrtsrv] - VRTSRV::Attach VM. Setting error code E_VS_FS_FAILED_TO_OPEN_VHD as Open Failed for some reason. VMName = <VMNAME> !
 [fsys\vrtsrv] - VRTSRV:information IsOperAborted 0
 [fsys\shared] - Detach from Shadow?Copy?Components
 [ndmp\loops] - BACKUP_LP_ENV::AttachToDLE() failed to attach to (null). Reason is 0xa000964c
 [ndmp\loops] - LP_ENV::MsgError: error 0xa000964c processing object <Unknown>
A hotfix is now available for this issue in the current version(s) of the product(s) mentioned in this article. Refer to the Hotfix link under Related Documents at the end of this article to obtain the hotfix needed to resolve the issue.
Backup Exec 2012 Rev 1798 Service Pack 3 (TECH205351).