In windows 8 I simply can't install any version lower than 4.5.1 and on my experience if program needs net framework 3.0 then it will not run without it even if newer version is already installed. I think it's better to avoid Windows 8 and 10 at all cost until Microsoft finally learn how to do their work right.
It's impossible to install net framework 4.0 on windows 8, and also impossible to ununstall integrated 4.5.1. At least I know the root of my problem, thanks.
SDK doesn't working and I don't know why. Installed every file in "_CommonRedist" and "Binaries\Redist" and I still getting an error when trying to launch "XCOM 2 Development Tools" on my Windows 8.1 x64... "dotNetFx40_Full_x86_x64" says it's integrated with my system and cannot be installed. What should I do now?