Hero sample .blend files, artwork not visible (brown viewport)

I’m new to blender and interested in the new greasepencil functionality. I’ve downloaded Blender 2.80 and I’m trying to look at the sample scenes from the Hero film. When I open them the viewport is brown and I can’t see any artwork (see screenshot). This is the p027_sample_01.blend file.

Is this a graphics card issue?

I’m using a 2017 retina imac. Any pointers would be vey much appreciated!

On Windows, i’m getting even less from that sample… i think :poop: it is

Anyone, care to show what Linux presents?