When Granular Restore Technology (GRT) enabled Sharepoint agent backups are performed without the Advanced Open File Options (AOFO) setting, 'Use snapshot technology' enabled, incremental and differential backups will complete with exceptions:
Backup- SharePoint - 80\Content-DB 1 (SPS\SHAREPOINT\WSS_Content)
V-79-57344-5890 - The object was not found, or could not be accessed (Share point backup).
The item SharePoint - 80\Content-DB 1 (SPS\SHAREPOINT\WSS_Content)\WSS_Content in use - skipped.
This error occurs because AOFO snapshot backups are required for Sharepoint GRT to work properly for incremental and differential backups.
Edit the backup job properties and in the Backup Options page, click the 'Advanced Open File' selection and apply a check to the 'Use snapshot technology' checkbox. In general the checkboxes for 'Automatically select snapshot technology' and 'Process logical volumes for backup one at a time' should also be checked as they are by default.