Yes, unfortunately it gives the same error message.
I have tried:
'c:\MountPoint\CloneMount\'
'c:\MountPoint\CloneMount'
'c:\\MountPoint\\CloneMount\\'
'c:\\MountPoint\\CloneMount'
"c:\MountPoint\CloneMount\"
"c:\MountPoint\CloneMount"
"c:\\MountPoint\\CloneMount\\"
"c:\\MountPoint\\CloneMount"
c:\MountPoint\CloneMount\
c:\MountPoint\CloneMount
c:\\MountPoint\\CloneMount\\
c:\\MountPoint\\CloneMount
And now you got me to try with "/" instead of "\", which I hadn't thought of, but it gives the same message: New-SmClone : Input string was not in a correct format.
But as i said, "funny" thing is, that if i use a path that not exists like 'c:\MountPoint\Foo\', it gives me: New-SmClone : Invalid mount path: Path does not exist.