This issue can occur due to the following reasons:
1. The writers responsible for performing application-aware processes are in an unstable condition.
2. During backup job configuration, all volumes in the app-aware confirmation are excluded.
3. Another application or service may be using the VSS Service Provider.
To address the problem, consider the following suggestions:
Problem 1: Unstable Writers
1. Connect to the Backup-configured VM and check the log file at `C:\Program Files\Vembu\BackupForAWS\Server\BackupRestore\logs\<backup_name>\backup.log`.
2. If the error is "(The command status - True and command output - {"status": false, "error_msg": "writers are not stable"})," list the writers with the command `vssadmin list writers` in PowerShell or Command Prompt.
3. Identify any writers in an unstable state. Restart the Volume Shadow Copy Service in `services.msc` and check the stability of the writers. Proceed with the backup if stable.
Problem 2: Excluded Volumes
1. If all volumes were excluded in app-aware configuration, edit the job, remove the excluded volumes, and save the backup job.
2. Run the backup again.
Problem 3: VSS Operation Blockage
1. Check the log file at `C:\Program Files\Vembu\BackupForAWS\Server\BackupRestore\logs\<backup_name>\backup.log` for the error message "(The command status - True and command output - {"status": false, "error_msg": "StartSnapshotSet() is failed. hr=-2147212522"})."
2. If the error code is `-2147212522` or `-2147212529`, it indicates that the VM/Instance has a service performing VSS operations, blocking the shadow copy. Retrieve the provider ID from the Event Viewer log.
3. Use the command `vssadmin list providers` to get the providers running on the VM. Match the provider ID in the Event Viewer log with the listed providers.
4. Delete the identified provider in the registry editor (`Computer\HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\Services\VSS\Providers\`).
5. Restart the machine and schedule the backup.