Hi, Windows couldn’t create the snapshot needed for the backup. I’d check these services first:
Press Windows + R >> type services.msc >> press Enter.
Find Volume Shadow Copy and Microsoft Software Shadow Copy Provider. If either is Disabled, change it to Manual >> Apply. Click Start if it’s stopped, then retry the backup.
If it still fails, please send a screenshot of the complete error, including the error code and any additional information. Let me know the result, and I’ll follow up.