Oh...****.
I just took a look at the mod you posted. It looks like whoever created it named the VP file with it root_fs2.vp. I have no clue why they did that...but it means that you may have accidentally overwritten your retail VP file with the mod's, which you should never ever do.
Solution: Make sure your root_fs2.vp is the one that came with retail FS2 (Either uninstall and reinstall, or download the individual VP file from one of the links in the General Freespace forum.)
Then, extract the mod someplace (Not your Freespace 2 directory). Rename the VP something else..."revenge.vp" should be good and solve any precedence issues.
Then, make a new directory inside your Freespace 2 directory, call it "revenge". Copy all the files from the ZIP (including the newly-renamed revenge.vp) to that folder.
Finally, use the 'Mods' section of the launcher to select the revenge folder you just made. Start Freespace2 and see if it's fixed.
In the future, if you ever come across a mod that contains a VP file named the same as one of the original VP files, make sure you rename it to avoid confusion. You should never change, overwrite, or move the original VP files unless you know exactly what you're doing.
