backup fails for rds generated vm's

Hello!

The part of our infrastructure where the problem is:

- 1 physical server running server 2012 standard with the hyper-v role installed
- several virtual servers running on the above machine (also running windows server 2012) and one of them is configured for remote desktop services vdi
- several virtual clients (windows 8) generated by the virtual collection configured on the RDS server
- backup and recovery advanced server virtual edition 11.5 latest build installed on the hyper-v server
- all the virtual machines, including the hyper-v server are in active directory

The problem:

Not all the virtual machines can be backed up!

If the hyper-v agent uses local paths to reach a vm files then it's ok, the backup will be made, but if the path for a vm is a network path (the way RDS uses for the vm's in the collection), even if that share is on the hyper-v server, then the backup will fail!

To put it simply, all the virtual machines that are not generated by RDS are ok at backup and all the virtual machines generated by RDS will fail at backup - how do I fix this!?

See bellow a sample error:

Failed to perform the requested operation.
Additional info:
--------------------
Error code: 13
Module: 149
LineInfo: d1ab7fa1e56ec81c
Fields: $module : disk_bundle_vs_37975
Message: Failed to perform the requested operation.
--------------------
Error code: 236
Module: 16
LineInfo: 7bb42efe3c733241
Fields: $module : disk_bundle_vs_37975
Message: Internal error: Attempt to access emulated disk for non-initialized object.
--------------------
Error code: 94
Module: 83
LineInfo: 383ffdb092990e22
Fields: $module : hv_srv_vs_37975
Message: Failed to open virtual disk file '\\192.168.125.20\rds-vm\netland-collecti\sc-nld-4\Virtual Hard Disks\sc-nld-4.vhdx'.
--------------------
Error code: 212
Module: 83
LineInfo: 383ffdb092990dd9
Fields: $module : hv_srv_vs_37975
Message: Failed to create a multi-volume snapshot where files are located:
\ \192.168.125.20\rds-vm\netland-collecti\sc-nld-4 (virtual machine file location),
\ \192.168.125.20\rds-vm\netland-collecti\sc-nld-4\Virtual Hard Disks (virtual machine snapshot file location),
\ \192.168.125.20\rds-vm\netland-collecti\sc-nld-4\Virtual Hard Disks\sc-nld-4.vhdx (virtual disk file location).
--------------------
Error code: 209
Module: 83
LineInfo: 492281f19386255c
Fields: $module : hv_srv_vs_37975
Message: Failed to retrieve the GUID path for the volume that is associated with the specified volume mount point '\\192.168.125.20\rds-vm\'.
--------------------
Error code: 65520
Module: 0
LineInfo: bd28fdbd64edb8e0
Fields: code : 2147942487, $module : hv_srv_vs_37975
Message: The parameter is incorrect
--------------------