CobianSoft

This option works only when adding the source or the destination, not when running an existing task.

Ok, I now understand how it works.

I have tried the same task with or without UNC paths, as shown in the attachments.
It only works using the paths that starts with the drive letters. Using UNC paths is not working and it gave me the same error.

Best Regards,
Matteo

Quite strange. UNC path is after all the real path name.