V-79-40960-38521 error on daily backups

[Klinic]

Backup Exec 20.1 Windows Server 2012 R2 Hyper-V Host getting V-79-40960-38521 errors each day for the last 2 months and have not had a successful backup.  We have not made any changes to the VM's impacted.

Event Veiwer Event ID 10178, 10172, and 16010 all showing on the Hyper-V host with: 0x8007052F, no errors on the VM themselves.

All knowledgebase articles are for the same error but with with other exception codes. Our issue is codeing with: 0x8007052F

[Klinic]

Additionally whenever we stop/restart the VMMS service we get the following event in the Hyper-V-VMMS - Admin logs

The description for Event ID 19100 from source Microsoft-Windows-Hyper-V-VMMS cannot be found. Either the component that raises this event is not installed on your local computer or the installation is corrupted. You can install or repair the component on the local computer.

If the event originated on another computer, the display information had to be saved with the event.

The following information was included with the event:

<VM-Name>
42D78F54-D840-4460-B4C3-ED41C4A59B44
%%2147942432
0x80070020

The locale specific resource for the desired message is not present

vssadmin list writers does not return any errors

[RogRubin]

The 19000 event on Microsoft-Windows-Hyper-V-VMMS could indicate there is a failed merge operation and if that is happening for every VM then a larger activity took place some two months ago.
You might want as well verify that these alerts started at the same time the backup started to fail or if this is more a one off / additional issue for one or two specific VM's.
As the backups started to fail for all VM's on the same day 2 months ago, I would concentrate on what has changed from one day to the other two months ago, not just on the BE site but mainly on the Hyper-V site itself (not the individual VM's).