Symantec Backup exec 2010 stops exchange services.

Dear  Support Team,

I am usingSymantec Backup Exec 2010 Version 13.0. I have two symantec backup job for exchange server. One job is for frontend server full backup and other is for exchange backend server storage group full job using it via template and also have setting for duplicate job. Before all three jobs were running without issue. But now, if a job runs at the schedule time it stops frontend server services. The only solution for this is to restart the front end server. Kindly help where the things gone wrong. Enough disk space are there to take the backup job.

Regards.