You receive the following error in the backup report of your Exchange backup:
CExBackup::backupService:HrESEBackupSetup: Error Number 0xc800020e: An incremental backup cannot be performed when circular logging is enabled.
This is Microsoft Exchange related. To resolve the issue, please disable circular logging of the corresponding information store, and restart the "Microsoft Exchange Information Store" service afterward. After that, perform a full MS Exchange server backup instead of a transaction log backup. This would ensure that the data on server is all backed up properly.