Image failed to process. Invalid image ID


I'm new to WPMU and like what I see so far.

I am trying to load an image (Upfront/Customise and drag image placeholder)and it doesn't matter the size, naming or type jpg or png they all fail with "Image failed to process. Invalid image ID". This only happens on this site with this Scribe theme (Not tried other WPMU themes as yet). Images are loaded to the Scribe media gallery and can be added to any page but the second I hit "OK" it fails with the above message.

I can add these images to other sites or to this site when running other basic Wordpress themes.

I am running a local dev (Ampps). It is a clean Wordpress install with WPMU Dev and the Scribe theme and no other plugins.

I hope you can help.