Lethargy wrote:I installed version 3.7 with no problem, ....
I'm not so sure about that. You're not up and running yet anyway.

But we'll get you there. Please bear with us.
Also, I had pretty much the same problem with 3.6 before the latest version came out.
Ok. So we know it's not caused by 3.7 (and most likely not Chaos either... but we'll get there one step at a time).
I've tried every method imaginable to run the mod, ....
Ok. But Jb was wondering can you run UT2004 Ok? Can you fire up UT2004 and play, and can you do it with ECE content (ie: start by verifying that your UT2004 w/ECE is working).
And you said "something to that effect", but just to make sure, it's
-mod="ChaosUT2"
Alopexau wrote:Exactly the same error here too, ....
Actually, I'm not sure you have the same thing at all. It looks like yours might be standard issue of missing required files (I think maybe when it says GUI Controller that's what it means).
Azarael wrote:I opened the packages concerned in UEd ...
I can assure you it's not required to open any Chaos packages in UEd to get it running.

Yours is most likely install error as well.
I'd bet $2 of Dorian's money that each of these is install errors.
Please refer to ReadMe/Manual and make sure all required files are in place, and working, and then that all Chaos files are installed correctly.