Error backup Exchange 2010 en uno de los 2 nodos

APPLICATIONS:\Microsoft Exchange 2010: Backup of [APPLICATIONS:\Microsoft Exchange 2010] failed

: (CPSImportService::GetOperationStatus) ERR: Error calling operation Status, status=7015:'Import failed on bns93.bne.local. Reason: [null]'

NMM .. Error encountered performing snapshot import: PS .. Error during execution of snapshot import: 'Import failed on bns93.bne.local. Reason: [null]'

64034:nsrsnap_vss_save:NMM .. Error during import of snapshot: PS .. Error during execution of snapshot import: 'Import failed on bns93.bne.local. Reason: [null]'

.

63372:nsrsnap_vss_save:NMM .. Registration of snapshot set failed -- PS .. Error during execution of snapshot import: 'Import failed on bns93.bne.local. Reason: [null]'

NMM .. Close VSS backup service.

NMM .. Import Service is running... Closing now...

NMM PowerSnap has closed its services.

77175:nsrsnap_vss_save:NMM ..  completed commit replica with status of false.

10/20/15 16:18:36.007226 C:\Windows\SYSTEM32\DISKPART.EXE started, pid 11736

10/20/15 16:18:36.007226 C:\Windows\SYSTEM32\DISKPART.EXE waiting, pid 11736

Microsoft DiskPart versi�n 6.0.6002

Copyright (C) 1999-2007 Microsoft Corporation.

En el equipo: BNS93

Montaje autom�tico de nuevos vol�menes deshabilitado.

10/20/15 16:18:37.021239 waitchild reaped, pid 11736

NMM .. ending RM session.

37959:nsrsnap_vss_save:Error interno.

.

63335:nsrsnap_vss_save:NMM backup failed to complete successfully.

nsrsnap_vss_save(390): Entering SendRecoverJobFailure().

Internal error.

10/20/15 16:18:37.146041 Clearing ssn session 0x00000000085055B0 (fd 1200) from [0], ssn_max_pollfd 0

nsrsnap_vss_save(402): Exiting SendBackupJobFailure().

nsrsnap_vss_save: Sending backup status to nsrsnap

102333 1445350717 3 0 0 2168 3392 0 bns93.bne.local nsrsnap_vss_save NSR error 21 Exiting with failure. 0

10/20/15 16:18:44.571736 Clearing ssn session 0x00000000014537F0 (fd 1332) from [0], ssn_max_pollfd 0

Hemos probado de todo lo indicado en casos con el mismo error y no se soluciona.

Tenemos la versión de los clientes de Networker en los 2 nodos de DAG subida a la 8.2.1 y de NMM también a la 8.2.1 y el servidor de Networker la 8.2.0. Desde que subimos de versión no hemos parado de tener errores que se han ido solventando hasta este que llevamos 4 semanas sin backup y no damos con la solución.

Gracias

Un saludo