Don’t know if it will help, but from a Robocopy source web page:
If either the source or desination are a “quoted long foldername” do not include a trailing backslash as this will be treated as an escape character, i.e. "C:\some path" will fail but “C:\some path\” or “C:\some path” will work.
Robocopy will fail to copy files that are ‘locked’ by other users or applications, limiting the number of retries with /R:0 will speed up large jobs.
Worth a try putting the double slash in just in case or checking if the folder contents are locked by another programme. Other than that, don’t know Chris :shrug: