You need to actually install FS2_Open
What you've installed are the Media VPs which are the new graphics and models to make FS2_Open look good. What you haven't actually installed is the new executable files that can deal with the new stuff.
In addition you haven''t actuially installed to the correct place. Installing the media VPs directly to the main folder is just asking for trouble.
Take a look here
for instructions on what to do.
Better check that you have the most recent version of mv_zPack too. I suspect yours is old.