Symptoms

1. You have Hyper-V 2019 environment with Acronis Backup Agent for Hyper-V installed
2. Agent for Hyper-V sometimes loses assigned license and backups fail with an error similar to the following one:

   Functionality 'pcBackup' is not available. Please use the appropriate license

3. If you reassign the license from Settings->Licenses, after several days the license assignment may be lost again (possibly after a machine reboot) and future backups would fail with the same error

Example of full error log: click to expand

| trace level: error 
| channel: tol-activity#B056AF08-3D54-4273-AAD7-1B5EBEC90E30 
| line: 0x4a8728dc8a1c9583 
| file: e:\21\enterprise\common\tol\gating_activity.cpp:221 
| function: Tol::`anonymous-namespace'::BusinessActivityTracker::OnCompleted 
| $module: mms_vsa64_11010 
| 
| error 0x1350016: TOL: Failed to execute the command. Backup plan 'NUC - Imagem' 
| line: 0x8d165e86fb81959b 
| file: e:\21\enterprise\common\tol\command\command.cpp:461 
| function: Tol::`anonymous-namespace'::MakeFailResult 
| CommandID: D332948D-A7A9-4E07-B76C-253DCF6E17FB 
| $module: mms_vsa64_11010 
| 
| error 0x1350016: TOL: Failed to execute the command. Backup plan 'NUC - Imagem' 
| line: 0x8d165e86fb81959b 
| file: e:\21\enterprise\common\tol\command\command.cpp:461 
| function: Tol::`anonymous-namespace'::MakeFailResult 
| CommandID: D332948D-A7A9-4E07-B76C-253DCF6E17FB 
| $module: agent_protection_addon_vsa64_11010 
| 
| error 0x2980064: Functionality 'pcBackup' is not available. Please use the appropriate license. 
| line: 0xbfc205b2f53c251e 
| file: e:\21\enterprise\licensing\enforcement\api\parse_response.cpp:125 
| function: Licensing::MakeEntitlementIssue 
| FeatureID: pcBackup 
| $module: agent_protection_addon_vsa64_11010 

If you check mms log under C:\ProgramData\Acronis\BackupAndRecovery\MMS\mms.0.log, you see a warning similar to the following one:

| error 0x1403f4: WMI 'ExecQuery' failed for query '%ls'.
| line: 0xc523d9a02d03d56e
| file: d:\1164\core\winex\wmi_acc.cpp:323
| function: Windows::WMIClass::Select
| Query: SELECT * FROM Win32_OptionalFeature WHERE InstallState=1 and Name='Microsoft-Hyper-V'
| $module: hv_srv_vsa64_12422
|
| error 0xfff0: Catastrophic failure
| line: 0xbd28fdbd64edb8fb
| file: d:\1164\core\common\error.cpp:317
| function: Common::Error::AddHResult
| code: 0x8000ffff
| $module: hv_srv_vsa64_12422

Cause

Issue in the product.
It is connected to WMI failure, which causes incorrect enumeration of Hyper-V instances after Hyper-V host restart. As the result the Hyper-V host instance is deleted from MMS database and the license for it is dropped. 

Solution

This issue has been fixed in Update 4 (Build 12730), please update to the latest build.

To work around the issue without updating, manually reassign the license to the Agent for Hyper-V (from Settings->Licenses section of web console) when you encounter such errors.