I have a simple android app with 2 activities -- game mode selector and game activity. When I start game activity for the first time, everything is ok, but when I navigate back to selector and then again to game activity, game crashes on first call to GraphicsDevice.Viewport.Unproject.
What can cause such a behavior?
P.S. I implemented Unproject based on this gist -- it works correctly, but the question remains -- should I expect that other objects are corrupted after restart?