Hyper-v Virtual Standby export fails to complete "Illegal operation attempted on a registry key that has been marked for deletion (4040857)

After exporting the volumes, the job fails with the following error:

The operation with VHD virtual disk failed
The remote Hyper-V operation has failed

Exception chain:
Illegal operation attempted on a registry key that has been marked for deletion. (Exception from HRESULT: 0x800703FA)
Unknown WMI error: Illegal operation attempted on a registry key that has been marked for deletion. (Exception from HRESULT: 0x800703FA) WMI query: SELECT * FROM Msvm_VirtualSystemSettingData WHERE VirtualSystemIdentifier = '171CBC45-01E5-4ED7-8034-23AE759CF8AC' AND VirtualSystemType = 'Microsoft:Hyper-V:Snapshot:Realized' -namespace root\virtualization\v2
The remote Hyper-V operation has failed
Call to service method http://vcvmr2:8010/apprecovery/api/hypervagent/hypervagent/2aa37893-4d43-4da6-afbe-648e0b8c97ff/getSnapshotsCount GET failed: The remote Hyper-V operation has failed
The operation with VHD virtual disk failed
One or more errors occurred

Core is not sized correctly

This cause the Core to hang while creating the export.

You can see in the Core logs the next event ID pointing to Export registry keys been corrupted

Source: Microsoft-Windows-Kernel-General
ID: 5
Date: 11/07/2017 08:14:12
Description: {Registry Hive Recovered} Registry hive (file): '\??\C:\Windows\TEMP\ExportPostProcessing-a14ebebe-9173-4db0-952c-96669c95b2f6\Windows\system32\config\system' was corrupted and it has been recovered. Some data might have been lost.

Increase Core resources. Validate with the Sizing Guide the recommended resources the Core needs to be able to work correctly.

Additionally you can opt to make Performance Tuning changes to the Core.

Verify if Dedupe cache size is bigger than the size recommended depending on the amount of RAM installed.