QuickLook no longer displays files after 6.6.2 upgrade

I recently upgrade my OmniGraffle to 6.6.2, and now all the quick look images no longer work and are replaced with generic omnigraffle icon images.

OS is 10.12.2 and all other quick look files work fine.

I have rebuilt the Spotlight database, removed pref’s etc etc but still no go.

Any ideas?