Error backup Hyper-V 2012

I have the following error message on two HyperV-V 2012 platforms have reinstalled twice agents and error, which could not be removed?

Backup- VRTSRV::\\H----------\Hyper-V?HA?VM\SRDCHM02

  Unable to attach to .

V-79-57344-33899 - The resource could not be backed up because an error occurred while connecting to the Agent for Windows. The correct version of the Agent for Windows must be running on the target computer.

Backup- VRTSRV::\\H---------\Hyper-V?HA?VM\SRPRINTHM01

  Unable to attach to .

V-79-57344-33899 - The resource could not be backed up because an error occurred while connecting to the Agent for Windows. The correct version of the Agent for Windows must be running on the target computer.

V-79-57344-34009 - An error was encountered creating on-disk catalog. If this is an incremental backup, cataloging of the generated media may not work correctly.

V-79-57344-34009 - An error was encountered creating on-disk catalog. If this is an incremental backup, cataloging of the generated media may not work correctly.