[Snapshot Pro] Snapshot failing to run since update

Since updating Snapshot Pro it fails to run (now have same fault on several websites). After the system check, as it starts to do a backup I get this message:

AAA An unknown response returned from Snapshot backup attempt. Aborting. Double check Snapshot settings.

I haven't changed anything in the settings, although the interface is different, I can't see what is wrong. (Had hoped to resolve this via live chat, but it refuses to believe browser Cookies are enabled!).

Thanks Kelvin