I can't to restart failed object - DP 6.0

HI
 
I can't to restart failed object - DP 6.0

I have different problem with backups but when I fix them I can not restart sessions in error

A client backup failed, but it doesn't show in session report, so if I try to restart it with "Restart failed object", I get "None of the Disk Agents completed successfully"
I still have to run the job again for backup