Occasionally Exchange API errors are returned in the backup logs for Exchange Information Store backups. They appear similar to the following in the logs:
Exchange backup API returned: 0xC7FE1F45 (-939647163)
Exchange API Error 0xC7FE1F45
This error results from the depletion of free space on the drive containing the transaction logs. Removing unneeded transaction logs can resolve this. More information about this can be found here.
Exchange API Error 0xC80001F9
This API error may be caused by either a backup run on an information store which has circular logging or is already running a backup. Steps for troubleshooting this error can be found in this article. Additionally, you can try the following steps:
- If another program is backing up Exchange, stop those backups and run the backup from our software again.
- If the folders that contain the Exchange database are selected in a File and Folder backup, remove those folders from the backup set.
- Users of Windows Server 2003 can try the steps from this Microsoft article.