you likely have an error (or more) in your game code (mistakes you made as you made your game) ...
are you just doing this via the browser~online or are you using the desktop~offline (downloaded) version of quest ???
if you're doing it online~browser... if you can, you'll need to download your own game to get your game file. If it's a *.quest file... you may not be able to open it up into your code for it...
otherwise, if you got your own game file, you can just right click on the game file itself, and choose to open, selecting some text software to open it with (such as notepad, wordpad, notepad++, text editor, etc), and now that you game code is opened up... then it'll need to be troubleshooted (scoured) for the error(s), and fixed up.
there's two types of mistakes you can make:
mistakes that prevent your game file from even loading~opening up into the GUI~Editor and~or being unable to start~play your game. mistakes~errors which prevent the required "initialization" of your game file (and~or any included library files too).
mistakes that cause errors during runtime (during playing the game, for example a battle event may not work due to an error~mistake in your code for that battle event in game)
for the most part... you should be able to get into your file (if you can only download a *.quest file and it can't be opened into your game~source code, hopefully you can email Alex and he can get your your game file converted into a file format + code format that you can open up into its game~source code...), and thus it's fixable.
don't be scared by any errors or not being able to get into the GUI~Editor, as all it means is that there's mistakes that you created when trying to make your game, and those mistakes are causing the problems, which can be "easily" fixed (usually the hardest part is just finding the errors in the code... laughs. Like finding needle~s in a haystack... The stupid typo~simple mistakes are the smallest and thus hardest to locate~spot, argh...)
or, if you're doing this online~browser... maybe just the site is having issues at the moment ....