Operating system error: The shadow copy provider had an error. Check the System and Application event logs for more information.
Acronis Cyber Backup utilizes Windows Volume Shadow Copy Service (VSS) writers to perform backups. VSS is a Windows operating system component that provides the functionality to take a snapshot of a volume. If VSS malfunctions at any step of snapshot creation, this will cause the snapshot failure and lead to backup errors, since Acronis Cyber Backup relies on successful snapshot creation by VSS for capturing data for backup.
This article provides guidance on how to troubleshoot VSS issues that cause Acronis backups to fail with volume snapshot-related errors.
If a VSS failure is detected that cannot be fixed using the recommendations from this article, the problem should be addressed to Microsoft and/or researched using their support resources.
1. Download VSS Doctor to investigate and troubleshoot issues with VSS on the affected Agent machine
2. Check Windows Event log for VSS-related errors and fix the issues.
Open the Windows Event Viewer (press Win+R -> type eventvwr.msc) and check the Windows Logs, Application and System. Look for entries occurring around the time when the issue occurred or just before that.