Looks like you might be having an issue creating the VSS snapshot.
11912 2fd0 04/16 23:54:02 45757 CRegistryWriterBackup::GetWriterFilesByType() - args.snap->GetSnapshotPath(bstrPath.m_str, shadowVol) - [FAILED] 0x80004005
Check if there are any releated Windows Event errors and ensure that there is adequate space on the drive.
If you see Windows errors similar to the following: [DESCRIPTION] The oldest shadow copy of volume C: was deleted to keep disk space usage for shadow copies of volume C: below the user defined limit.
I recommend that you increase the shadow copy space on the drive for each volume on the machine.
Right click on the volume>Configure Shadow Copies and set the limit for shadow storage on the Volume to either no limit, a larger limit or put it on a volume that you can set it to no limit.
If it continues to fail after that, then it is recommended to open a support ticket so a technician can review the full log set and continue troubleshooting with you.
CommVault Customer Support
24/7 Support Hotline#: 1.877.780.3077