All my content is in external runtimes (except the !DAZ folder, and other similar folder required for morph injections). I've found Poser runs a lot faster if you have as little content in the Poser folder as possible. I have SR2 installed, and have no problem with Koz's hair.

I tried re-downloading the Short Hair Evolution, and it worked fine if I just installed it directly to the runtime.

It shows as wireframe because that's how Koz designed it. A lot of hair designers do that.