several Campaign Maps I want don't load in-game & it's driving me nutso

[Verdun]

I know there are plenty of tutorials that explain how to make custom campaigns (some coming with the friendly observation "making campaigns is SO easy") but they don't explain why this isn't working, or at least I am completely lost as to what part of the turorials I missed

BASICALLY:

If I create any dumb empty map (see: "Bullshitemptymap I hate") and import all of my trigger+variable data and all my custom object data and add it to a campaign, it works perfectly fine (see: "Dummy campaign with empty map I hate").

BUT! if I try to add one of my finished maps with those same triggers+variables and custom object data (see: "Map I want"), clicking the button on the campaign screen just makes the screen fade to black and then return back to the campaign screen as if to mock me (see: "Dummy campaign with map I want").

The custom campaign accepts the maps created in 5 seconds but rejects the maps created in 5 hours.

Could somebody help me do some troubleshooting here? What is it with my detailled maps that makes loading them in the campaign so impossible?

 

[Verdun]

Update:

I made a copy of the map and deleted ABSOLUTELY EVERYTHING, from triggers to imported models, and YAY, that does the trick, NOW my campaign is happy to open that map
NOW I could play it, provided it contains absolutely nothing


Guess now I'll have to retrace my steps and see what of the many, many, many things I added brought the original brain-meltingly infuriating doom

UPDATE of the Update:
It is somewhere in the imports. I kept everything the same except deleting all imports, and it works fine.
So then I started carefully ADDING imports again, and as of the first 6 custom models, no problems. Somewhere in the dozens and dozens of models, there must be one that ruined everything. Oh well. Back to the investigation.

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CONCLUSION:

It was the custom music file. Works 100% in normal map tests, but in the campaign it just had to crash everything.

I kinda want/need custom music, so I guess that's a puzzle for another day.
Lost almost 12 hours with this.

12 hours.

EDIT: The campaign accepts NO custom sounds whatsoever. Might be worth a separate thread. Or maybe it's something weird like you have to import the sound to the campaign import instead of the map import. Uuuuurgh.

Re-EDIT: THAT'S EXACTLY WHAT IT WAS ARE YOU KIDDING ME, WHY


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Takeaway for any future idiot archeologists who might find this:

1- If an imported file works in the regular map and not in the campaign, it's an issue due to the campaign system (no "Duh"s, please, I'm so tired).

2- The campaign system is, apparently, that some files (not units or textures it seems, but certainly sounds) need to go exclusively in the campaign import, do NOT import wavs or mp3s into the respective maps, I guess.