Quite simply, running the game in debug mode for me causes a very inconsistent, non-logged crash that throws no errors. The  debug build just closes itself.

What seems to happen is, it will load rooms until my title screen, but either going to a room or restarting the game will both make the application freeze, and then subsequently terminate itself. I've no idea what could be going on besides that.

This is an example of the log before and after the crash.

Edit: so i think a rogue computer theme was to blame, as i've not reproduced since switching. will update if anything happens

Pretty mysterious, considering that GMLive does not do any "unsafe" operations at all (the single exception to that being the shader replacer extension, which is very careful with what it does).