NetBackup Snapshot Manager Rollback Restore fails with "Request failed unexpectedly: 'dict' object has no attribute 'managed_disk'"

Problem

NetBackup Snapshot Manager Rollback Restore fails when VM was deployed using a Gallery image.

Error Message

Job Details:
Sep 18, 2023 4:41:54 PM - Info nbcs (pid=374932) Start
Sep 18, 2023 4:43:54 PM - Error nbcs (pid=374932) Failed to restore snapshot for asset: azure-vm-<assetid>
Sep 18, 2023 4:43:54 PM - Error nbcs (pid=374932) Request failed unexpectedly: 'dict' object has no attribute 'managed_disk'
Sep 18, 2023 4:43:54 PM - Info nbcs (pid=374932) End

Error in the flexsnap.log:
Message: The client '<clientid>' with object id '<object_id>' has permission to perform action 'Microsoft.Compute/virtualMachines/write' on scope '/subscriptions/<subscription>/resourceGroups/<resourceGroups>/providers/Microsoft.Compute/virtualMachines/<VM>'; however, it does not have permission to perform action 'read' on the linked scope(s) '/subscriptions/<subscription>/resourceGroups/<resourcegroup>/providers/Microsoft.Compute/galleries/<gallery>/images/Windows_2019_Mutable/versions/latest' or the linked scope(s) are invalid."

Additional permissions that can cause the same error:
flexsnap.GenericError: (LinkedAuthorizationFailed) The client '<clientId>' with object id '<objectId>' has permission to perform action 'Microsoft.Compute/virtualMachines/write' on scope '/subscriptions/<subscriptionId>/resourceGroups/<resource_group>/providers/Microsoft.Compute/virtualMachines/<virtual_machine>'; however, it does not have permission to perform action(s) 'Microsoft.KeyVault/vaults/deploy/action' on the linked scope(s) '/subscriptions/<subscriptionId>/resourceGroups/<resource_group>/providers/Microsoft.KeyVault/vaults/<key_vault>' (respectively) or the linked scope(s) are invalid..Code: LinkedAuthorizationFailed.Message: The client '<clientId>' with object id '<clientId>' has permission to perform action 'Microsoft.Compute/virtualMachines/write' on scope '/subscriptions/<subscriptionId>/resourceGroups/<resource_group>/providers/Microsoft.Compute/virtualMachines/<virtual_machine>'; however, it does not have permission to perform action(s) 'Microsoft.KeyVault/vaults/deploy/action' on the linked scope(s) '/subscriptions/<subscriptionId>/resourceGroups/<resource_group>/providers/Microsoft.KeyVault/vaults/<key_vault>' (respectively) or the linked scope(s) are invalid."

Cause

The Microsoft client account is missing required privileges to access the image the restore VM was based on.

Solution

Review the error and provide the required permissions toaccess to the image listed in the error.

For example:

Microsoft.Compute/galleries/images/read
Microsoft.KeyVault/vaults/deploy/action