https://bugs.freedesktop.org/show_bug.cgi?id=79659
--- Comment #5 from Marek Olšák maraeo@gmail.com --- The problem is Unigine don't know how to use GLSL, again.
There is "#extension GL_ARB_sample_shading : enable" in the middle of (all?) shaders. This is not allowed by any GLSL specification. All #extension directives must occur before any non-preprocessor tokens, which pretty much means "at the beginning of shader code".
What I see: Valley is loading. Then there is hang and it recovers successfully. After that, Valley seems to have exited. That's all.