Monthly backup error

Hello,

I have an error for the monthly backup but the daily backup is good.

I don't understant the error :

"

WARNING : Of : BSM@adapei-hpdp.adapei26.local "Full_Journaliere_Mensuelle" Heure : 30/10/2015 21:00:08

[61:17102] Number of licences "drive extension for Windows/NetWare/Linux" inadequate.
The session is waiting some devices are released

[WARNING] Of: BSM@adapei-hpdp.adapei26.local "Full_Journaliere_Mensuelle" Heure : 30/10/2015 21:00:08
[61:2013] Some devices of save are busy. The session is waiting all devices are released.

[Critique] De : BSM@adapei-hpdp.adapei26.local "Full_Journaliere_Mensuelle" Heure : 30/10/2015 22:00:36
[61:2015] The waiting time for the released of devices is exceeded.
The session will stop.

[Critique] De : BSM@adapei-hpdp.adapei26.local "Full_Journaliere_Mensuelle" Heure : 30/10/2015 22:00:36
No Disk Agent was successful.
The session failed.

"

Thanks for your help,

BR,

PHE Victor

Quadix Support.