Infinity Blade assets cause shaders to be recompiled constantly - why?!

I began poking at Infinity Blade assets last night and it’s impossible to work with them as every time I try drag’n’drop any static mesh from content browser into my scene, UE4 freezes (not quite, but can’t really do much) and I get 100 something shaders recompiling. And it’s like that for every single assets from Infinity Blade :confused:

And on top of that, they appear pitch black in the viewport (and in PIE) when using ES2 preview mode. It’s odd, since those assets are made for mobile platforms.

How do I solve both issues ?