Ok, here's what I got:
I remembered what happened the first time, because I downloaded the installer 4 more times and got the same result: The installer works fine, but once the installer finished, a error message pops up, saying "an error occurred with the installation." I click "Ok," the installer says It has successfully installed RoM: AND , I press Finish, and the installer stops responding. This happened the first time, not the second time, and the subsequent 3 times I downloaded the installer. I eventually stopped the unresponsive installer, but never got RoM: AND to show up in the list of Mods.
The second time when it got to 2/3rds of the way may have been a corrupt download, but there has to be more to it. I think I'm gonna try Deleting Civ entirely and re-downloading it again, since I have a lot of mods I'd like to get rid of anyway. I don't think my 1st and 3rd-5th copies of the installer are corrupted, so I'll run the 7zip program as well and see what I get.
EDIT:
Psyringe said:
If you have 7zip installed, you can open the archive with 7zip and then choose "test archive". This will simulate an extraction without actually trying to write the files anywhere, so it's a good method to test whether the archive is corrupt or whether something else is amiss.
I downloaded 7zip, and the program cant interact with the archive at all. I copied it to my desktop, attempted to "test archive" and a report box pops up saying 7zip cannot test the archive, with a similar result for the "open archive" and extract archive" commands. This would indicate that the archive is corrupt, but I downloaded the file 5 times! and I know I didn't just copy the file, I'm running Google Chrome, and it took a substantial amount of time to download each one.