Separate names with a comma.
That is actually very helpful. Still doesn't explain why you get a "invalid configuration file" which seems like a Parallels software issue. But...
Concur with @OlafV1 - disabling the above "Smooth Scrolling" setting, in VM > "Configure..." [Cog] > Hardware > Mouse & Keyboard is what slowed...
Just to add an opinion, I think understanding VM configuration, preferences etc. is much cleaner with the separate dock icons. And it makes sense...
