- AOFO: Initialization failure on: "\\JCC-SBS\Microsoft Information Store\First Storage Group". Advanced Open File Option used: Microsoft Volume Shadow Copy Service (VSS).
V-79-10000-11234 - VSS Snapshot error. The maximum number of snapshots for this volume has been reached. Microsoft Volume Shadow Copy Service (VSS) will not allow any more snapshots.
The Advanced Open File Option was set to Automatically select open file technology - I changed this to use "System - Use Microsoft Software Shadow Copy Provider".
After making this change, I tested another backup and it completed successfully.
Interestingly, if you read the error it was already using the Microsoft Volume Shadow Provider yet it failed. Hardcoding it in the settings of the backup job did the trick.