You probably have a problem with some configuration files, because everything works fine for me. Good engine. But there is one drawback. There are no underwater effects. When the player is underwater, it seems that he is simply hanging in zero gravity. Or maybe I did not find where this option is turned on.Yeah, I have same build and get the errors (when I attempt vanilla quake and try to enter a difficulty level portal, I get "error" instead of Easy, Medium or Hard. Then It crashes a few minutes later. Must be one of my cfg files since Ironwail and vkQuake run flawlessly.
Try this version of the launcher. It's almost final. I ran Zircon on it.