From the knowledge base, these are the relevant troubleshooting steps and checks for Active Backup for Business backup errors:
1. Check the backup task status and details:
- In Active Backup for Business > Activities > Task History, review the details for the task.
- The agent status can show Partial success or Error when one or more errors occurred during backup.
2. If you see Windows VSS-related errors:
- Press Windows key + R.
- Enter systempropertiesprotection and click OK to open System Properties > System Protection.
- If Synology VSS HW Provider appears in the list of VSS providers, uninstall Synology Storage Console for Windows on the computer before retrying the backup.
- Note: the System Protection tab is unavailable on Windows Servers. In that case, install Windows Server Backup and perform a system backup. If there are issues with Windows Server Backup, contact Microsoft Support.
3. If the error is 0x241:
- Update your Windows operating system.
- If the problem persists, make sure Windows ADK is installed by Synology Active Backup for Business Recovery Media Creator.
- If you previously installed Windows ADK manually, remove it and reinstall it using Recovery Media Creator.
4. If the error is -1, -2, or -3 on Mac:
- Restart your Mac in macOS Recovery mode.
- Open Disk Utility.
- Check both the startup volume and the data volume for repairs.
- Repair storage using Disk Utility.
5. Agent/version-related fixes from the release notes:
- Fixed an issue where extending volumes on Windows might result in incomplete backups.
- Fixed an issue where backing up multiple block devices on the same general disk on Linux might result in incomplete backups.
- Fixed an issue where backing up Macs with OpenCore Legacy Patcher might fail.
- Fixed an issue where file restorations might fail.
- Fixed an issue where rebooting Linux with kernel version 6.4 or higher might result in incomplete backups of /dev/sdx.
If you want, I can help you map your exact error code to the matching item above.
Sources used: [1], [11], [12], [14], [15], [16]