your global macros are NOT stored in the campaign!! they are stored in your registry (assuming you're running windows).
Usually I strongly advise against the use of global macro (I still do) but in you're case it might have saved your bacon!
I had a quick look at the campaign file and i noticed that your content.xml file is a whopping 250Mb. So no wonder you're running out of mem. Interestingly enough, the file is not corrupted, so Im *really* curious what the hell you did. I'm trying to open it in np++ to check.
It indeed makes your file unloadable, though it might be possible on a pc with massive amount of mem.
edit: ok checked the xml and apparently is the '<exposedAreaMeta>' which screws things over. Now this is not really my cup of t, but I would guess that this has to do with exposed VBL (which can get massive). Should you be able to load then a simple ctrl+o (or ctrl+shift+o, not sure) resets that lot. Alas you can't.
edit2: I gave it a shot myself, here's your corrected campaign: https://www.dropbox.com/s/alprz9h8ux65u ... cmpgn?dl=0
Although the VBL layers was still there on the castle, I removed it cause that caused the issue. My advice is to apply one solid VBL layer and then cut out the pieces players can see. That has never failed me.