Ahhh yes. The horrors of XDK.
Try selecting the projects tab THEN close XDK. When you re-open, then you can switch to the XDK emulation screen then it SHOULD start playing the game now.
Be sure not to close XDK while the emulation screen is active otherwise you would have to close an re-open again.
1 - Open the simulate: black screen.
2 - Go to the project tab and close the XDK.
3 - Re-open and still black screen.
I had a similar issue. In my case it was because y had used UTF-8 characters (such as Ä, É, Ñ, etc.), so make sure your project files only use ASCII characters (these are the characters you use when you write in English).
I'm not using non-ascii characters