Okay, so, I edited a couple of values in DatEdit 1.5b, had it export to self-executable patch, and opened the newly-created modfile. Only... nothing happened. I wondered if maybe it was specific to my mod but... I can't open ANY modfile... so has this happened to anyone else and is there a fix? x_x

"had it export to a self-executable patch"
DatEdit doesn't save .exe, only .dat. Do you mean you used WinMPQ/MPQCompactor and MPQDraft/FireGraft to make the .exe?
As in StarCraft didn't start, it crashed, none of your changes seemed to be in effect, or what? Specifics are important.

The simplest thing that could be done here would simply be to upload the mod itself so that one of us can look at it and see if we can find a problem.

DatEdit is able to export to a self executable Starcraft patch.

I would suggest downloading DatEdit v1.5d and see if it makes a difference.

Make sure that SC is closed when you execute the .exe. Otherwise nothing will happen.

Like FlyingHat said, it can do that now >_>.
Well, if it had crashed that would mean something happened, now doesn't it? But yeah, it didn't start Starcraft; not even the other mods I had from SEN ran.

Well, it wasn't only my mod that wasn't working, but I'll try it out anyway and post the results later.

I'm pretty sure it was, but I'll triple check next time, just to be sure.