Backup of Hyper-V virtual machine unsuccessful using DPM 2010 or DPM 2012

You can have a problem backing up a virtual machine using DPM 2010 or DPM 2012. In my case, the backup ended with error:

An unexpected error occurred while the job was running. (ID 104 Details: The parameter is incorrect (0x80070057))

After investigating the issue using VSSADMIN I realized that everything in VSS is ok. Creation of manual snapshots in guest and host computer were successful.

The commands to try manual snapshot are:

• vssadmin create shadow /for=C:
• vssadmin list shadows
• vssadmin delete shadows /for=C:

So finally I found out that in the virtual machine configuration the path for VHD file contained double-backslash.

After removing the extra backslash, everything worked like a charm.