The linked image is from Crowd Navigation. The black is the terrain and objects. The white is the character. All samples have this error, and I suspect that there is a similar problem in the editor as well, but I haven’t explored it enough to confirm.
It looks like materials aren’t loading to me, but I’m new to Urho3D, so if anyone knows what might be going on I would be very excited to get this fixed.
Linux Mint 17.1
Radeon mobile card with mesa graphics drivers
If you think that this is a hardware issue I can get a full dump of system specs.