How do I interpret these error messages

Recently reinstalled windows... suddenly my game won't compile and run, get this error message...

[quote:emizjlaz]Javascript error!

SyntaxError: illegal character

http://localhost:50000/data.js, line 3810 (col 60)

This is either a bug in Construct 2 or a problem in a third party plugin or behavior - please report it to the developer!

Assertion failure: Unable to load project: no JSON model available. Usually this means an error has prevented the browser loading a script. It may be a bug in Construct 2 or a problem in a third party plugin. Check the browser's error console for more information.

Stack trace:

assert2@http://localhost:50000/preview_prelude.js:12:4

Runtime.prototype.load@http://localhost:50000/preview.js:914:3

Runtime@http://localhost:50000/preview.js:285:3

cr.createRuntime@http://localhost:50000/preview.js:5186:3

—://localhost:50000/:167:4

x.Callbacks/l@http://localhost:50000/jquery-2.0.0.min.js:3:24576

x.Callbacks/c.fireWith@http://localhost:50000/jquery-2.0.0.min.js:3:25388

.ready@http://localhost:50000/jquery-2.0.0.min.js:3:2912

S@http://localhost:50000/jquery-2.0.0.min.js:3:548

Javascript error!

TypeError: cr.getProjectModel is not a function

http://localhost:50000/preview.js, line 915 (col 6)

This is either a bug in Construct 2 or a problem in a third party plugin or behavior - please report it to the developer!

Don't think it is a bug with Construct itself since this doesn't replicate anywhere else. My capx is ridiculously big. I am just wondering how to interpret this error message so I can find the problem. Since I reinstalled windows maybe there's still something I need to update? It was running fine before I had to reinstall windows.

You don't mention what version of windows , and have you updated service packs and display drivers .

Windows Vista 32bit--I've updated display drivers and service packs-- I have since tried running the capx on a different computer but I get the same error message, so now I'm thinking it might be a problem suddenly in the event sheet itself, or maybe an actual bug in construct 2?

I found a backup from a couple days ago. Not too much work lost. I don't know what I did to make the game unplayable. Moral of the story is keep multiple backups