Hyper-V-VMMS cannot connect to VHDs

Question

Hyper-V-VMMS cannot connect to VHDs

tocguy 160

This issue showed up today. Last VM run was on the 3/23. Only WUpdates since then are Defender defns. Now, cannot connect/launch any VMs.

Unsuccessful Troubleshooting:

Verified Full Access privileges to VHD folders on active account.
Discovered and set Hyper-V Settings for folder locations that had resorted back to their default folders:
1. Virtual Hard Disks
2. Virtual Machines
Deleted content of C:\ProgramData\Microsoft\Windows\Hyper-V\Virtual Machines Cache\ to remove VMs from Hyper-V Manager list thus re-enable import of the established VMs. Requires stopping Hyper-V Virtual Machine Manager service first. Import fails with Event errors 15040 and 16300.
1. Other Hyper-V-VMMS related Events included in this fiasco are 16320, 16410, 16420.
Removed/Reinstalled Hyper-V using Control Panel - Programs and Features - Turn Windows Features on or off.
Created new folder and copied content of existing VM's folder to it.
1. Register in-place fails with error 16300 and 15040.
2. Restore the VM fails with error 16300 and 15040.
Used Powershell to mount the VHDX file to extract important data only to discover via Disk Management that the drive is BitLocker encrypted! I DID NOT ENCRYPT THE VM! WTH????

Plz advise on nature of these errors and their resolution. In lieu of that, how may I extract important data files from the VHDX?

tocguy 160 Reputation points

2026-03-27T20:37:19.54+00:00

AI suggestions were insufficient so let's focus on Filter related issues as it seems to be the most relevant of the AI suggestions.

Following each boot, Event Log contains 4 Event 51's stating "An error was detected on device \Device\Harddisk3". However, the system has no Harddisk3. Is this associated with the VHDX?

Following these Event 51s are 6 Event 3s stating "Filter Manager failed to attach to volume '\Device\HarddiskVolume14'. This volume will be unavailable for filtering until a reboot. The final status was 0xC03A001C." Per DiskPart the PC's Volumes are numbered 0 thru 8. There is no Volume14. Hyper-V contains 2 VMs (neither are now launch-able) so again does this Event implicate a VHDX volume?

Plz advise...
tocguy 160 Reputation points

2026-03-28T14:43:28.2666667+00:00

This morning's cold boot did NOT produce the Event 51s and Event 3s mentioned above. Rather, they have been replaced(?) by 4 Event 16300s each stating "Cannot load a virtual machine configuration: The data is invalid. (0x8007000D)." There are 2 for each of the VMs that USED to exist in Hyper-V. On the one hand, the absence of the Event 51s and 3s could possibly be explained by the clearing of the cache mentioned in Step 3 of the OP above. The flip-side to this of course is why is the system then still generating these Event 16300s at boot time?

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tocguy 160 Reputation points

2026-03-27T20:37:19.54+00:00

AI suggestions were insufficient so let's focus on Filter related issues as it seems to be the most relevant of the AI suggestions.

Following each boot, Event Log contains 4 Event 51's stating "An error was detected on device \Device\Harddisk3". However, the system has no Harddisk3. Is this associated with the VHDX?

Following these Event 51s are 6 Event 3s stating "Filter Manager failed to attach to volume '\Device\HarddiskVolume14'. This volume will be unavailable for filtering until a reboot. The final status was 0xC03A001C." Per DiskPart the PC's Volumes are numbered 0 thru 8. There is no Volume14. Hyper-V contains 2 VMs (neither are now launch-able) so again does this Event implicate a VHDX volume?

Plz advise...
tocguy 160 Reputation points

2026-03-28T14:43:28.2666667+00:00

This morning's cold boot did NOT produce the Event 51s and Event 3s mentioned above. Rather, they have been replaced(?) by 4 Event 16300s each stating "Cannot load a virtual machine configuration: The data is invalid. (0x8007000D)." There are 2 for each of the VMs that USED to exist in Hyper-V. On the one hand, the absence of the Event 51s and 3s could possibly be explained by the clearing of the cache mentioned in Step 3 of the OP above. The flip-side to this of course is why is the system then still generating these Event 16300s at boot time?

Answer 1

tocguy 160

Resolved - create New VM and when prompted about where you'd like to store the new VM's VHDX select the option to connect to an existing VHDX. Browse to the existing VHDX location and proceed with the rest of the new VM process.

This worked 2/2 for resolving this configuration corruption issue for me.

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Answer 2

Thomas4-N 13,240 Microsoft External Staff Moderator

Hello tocguy,

Thank you for taking the time to come back and share the fix.

It sounds like your VM configuration files (.vmcx) had become corrupted — likely from the settings path reset — which is why re-importing and registering kept throwing errors like 16300 (0x8007000D "data is invalid"). The VHDX itself was untouched, just the config pointing to it was broken. Creating a new VM and attaching the existing VHDX essentially rebuilds that config from scratch, giving Hyper-V a clean, valid entry to work with again.

I really appreciate it. This kind of detailed update could really help others on the forum who run into the same issue.

tocguy 160 Reputation points

2026-04-02T15:16:20.93+00:00

The question remains as to Why were the VM settings reconfigured outside of the User's control and/or notification...
Thomas4-N 13,240 Reputation points Microsoft External Staff Moderator

2026-04-04T12:49:08.0233333+00:00

That's a valid point. After looking into it, I couldn't find any documented explanation for why Hyper-V settings would revert on their own — it's not something I can pinpoint with confidence.

Glad the new VM workaround got things working again though.

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Hyper-V-VMMS cannot connect to VHDs

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