Can't change language (engine issue)

So when I try to change loading policy from newer to another value, I can’t do it by some reason. And I can’t understand why.

After some time of research I can say that this thing is totally broken. I have create a new project and there I could change loading policy. After switching back to my project I could do it too, but after some time it was set to Newer again and I can’t change it.