I tried multiple times. Nothing changed that I did since when it was working a couple of days ago. I figured that someone may suggest verifying files, so I did that twice. The first time it DID find some things missing and re-downloaded them. The second time, of course, it passed. Still, I get the same error.

P.S. Can a Mod add the Runtime Error: 8003 () to the title, so the full error msg is listed? I meant to, sorry.

Looks like an installation problem .... Have you installed to another drive ?
Runtime error 8003 is "PATHCANNOTBEFOUND" so its not finding the folders

No. I just used it a couple of days ago. It's been on the same drive since I installed it.

Reinstall.

Seems to be something that I downloaded, causing an issue.
I've uninstalled and reinstalled multiple times. Every time I put the downloaded content back in the directories, when I reload the program, I get the same error. Installed with just the official DLC, it's all good. Obviously most of the stuff I downloaded is fine, but there's no way of telling which thing is causing the problem without going through it all one by one and trying it. I may do that tomorrow, because I have like 20 gigs of downloaded content and want to be able to use it. Just don't want to sit here all night doing that tonight. Thanks for the help guys.

The first place to start is with custom terrains as that's the part it's trying to load when it fails

Oddly enough, there was a single skybox, of all things. If it was there I got the error. If it was not, I didn't. But, I figured the same thing. That's the first think I tried. I'm back up and running now though. The help and suggestions are very much appreciated.