Acronis Backup: Activity fails with "Operating system error: The shadow copy provider had an error"

Error code: 50242
Module: 16
LineInfo: 0x3FEC04E376B8A1F7
Fields: {"$module":"SystemStateAgentProvider_vsa64_12960"}
Message: Failed to start creating the volume snapshot. To troubleshoot VSS issues, download and run Acronis VSS Doctor available at https://www.acronis.com/en-us/personal/vss-diagnostic-free-tool/
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Error code: 9
Module: 0
LineInfo: 0x02AACB7B2AB852AC
Fields: {"code":"2147754758","$module":"SystemStateAgentProvider_vsa64_12960"}
Message: The shadow copy provider had an error. Check the System and Application event logs for more information.

1.  Download VSS Doctor tool from one of the links below
   • For Windows XP/Vista/7, Windows Server 2003/2008
   • For Windows 8 and later, Windows Server 2012 and later
2. Launch the tool (local administrator rights are required).
3. Click Start diagnostic and wait until it completes.
4. Check out sections marked with 
5. Click Save log if you want to save diagnostic results as a plain-text report.
6. If a Fix issues button is available, click on it to see the exact solutions proposed by the tool and proceed if you agree.
7.  After fixing the found issues, click Start diagnostic again to check if all the issues were corrected.

1. In Event Viewer, Navigate to Windows Logs - System
2. Click Filter Current Log... on the right panel
3. Mark Critical, Error and Warning checkboxes in the upper part of the window. Expand Event sources list and select the following event sources: Disk, disk, NTFS, VSS, VolSnap (if search with these event sources returns no results, check all event sources)

4. Click OK and review warnings and errors recorded in the System event log, and look for any information related to the issue observed in Acronis software. Pay attention to events registered at the time the issue occurred, or just before that.

5. Repeat the search in Windows Logs - Application.

In some cases the event will contain instructions on how to resolve a particular error (e.g. a service is not available). For other events, use the Event ID and Source in your search to find additional information online.

See also Checking Windows Event Log for issues with computer environment