Error Message

​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
 

Debug of the Backup Exec Remote Agent on the Hyper-V host during Browse selection or Backup results in "error: 2"

BEREMOTE Debug Log:

[fsys\vrtsrv] - file 'X:\Hyper-V\VM\VMDISK_ECEC478D-A12F-4FAB-B4C4-08255C84FA5A.avhdx' is a VHD at the tail of the chain - hence it is considered application consistent and will be subject to used disk block analysis
[fsys\vrtsrv] - VRTSRV::Attach vhd 'X:\Hyper-V\VM\VMDISK_ECEC478D-A12F-4FAB-B4C4-08255C84FA5A.avhdx'
 - bevs::IVhdFileUtil::open_VHD: Failed to open file 'X:\Hyper-V\VM\VMDISK_ECEC478D-A12F-4FAB-B4C4-08255C84FA5A.avhdx', error: 2

 - the job is an abnormal state
 - Job Error Code: 32779
 - Job Error Description:
 - Job Error Summary Description:
 - Failed to get virtual disk info (0x8007800b)

[fsys\vrtsrv] - VRTSRV::Attach VM. Setting error code E_VS_FS_FAILED_TO_OPEN_VHD as Open Failed for some reason. VMName = !
[ndmp\dsss] | Cached attach failed: 0xa000964c
[ndmp\ndmpsrvr] - DSEnumerator failed with -1610574260: 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.​
 

Hyper-V Host Microsoft-Windows-Hyper-V-VMMS-Admin Event Logs:

Log Name:      Microsoft-Windows-Hyper-V-VMMS-Admin
Source:        Microsoft-Windows-Hyper-V-VMMS
Event ID:      15268
Level:         Error
User:          SYSTEM
Description:
Failed to get the disk information.

Log Name:      Microsoft-Windows-Hyper-V-VMMS-Admin
Source:        Microsoft-Windows-Hyper-V-VMMS
Event ID:      12240
Level:         Error
Description:
'': Attachment 'X:\Hyper-V\VM\VMDISK_ECEC478D-A12F-4FAB-B4C4-08255C84FA5A.avhdx' not found. Error: 'The system cannot find the file specified.' (0x80070002). (Virtual machine ID )

Note: These events are logged when the Hyper-V host cannot access some of the Virtual Machines virtual disks or snapshot files. 

A snapshot may have been manually created using Hyper-V manager.
The avhd/vhd file mentioned in the debug physically does not exist on the Hyper-v host. 

Solution 1: Delete any snapshots in Hyper-v manager for the problem Virtual machine and then power down the virtual machine.
Start the Virtual machine.
.
Attempt the Backup Selection.

Solution 2: 

If the problem file mentioned in the Hyper-V Event logs is accessible, but the events continue to be generated please contact  Microsoft support for further investigation.

Note: If the Virtual Machine configuration appears to be corrupt a restore of the Virtual Machine may resolve the issue. Please contact Microsoft support to determine if this is the best approach to the issue.
 

Attempt the Backup Selection.