I'm trying to find an answer regarding this problem:
I have this black square blocking the center of the vision on some apps (mozvr with firefox nightly 36.0a1 and kolor Eyes)
same problem with Direct HMD or Extended.
I'm running the last version of the runtime and everything is up to date, I also tried several resolutions but the problem is still the same.
If anyone has a suggestion to resolve this I would be happy to try it.
Windows 8.1 Pro
Intel i7 4770K 3.5GHz
GeForce GTX 770 Driver 344.75