According to the patch notes the current EA version of GMS 1.4 "added support for fullscreen - new GGS settings for this, plus Alt+Enter and window_..._fullscreen() all work". However, when I do a simple test on my Win 10 machine (with Creator Update): Create a room Place an object into it Set UWP Global Game Settings to start in fullscreen mode Run Project on UWP target (no YYC) then I simply get a black window - no fullscreen mode no content is shown. If I disable "start in fullscreen mode" then I see the normal window with the correct content. Could someone with the UWP target do a quick test and check if fullscreen works for them? Thanks a lot in advance!