AV-8B Harrier II missing gun?

[giopanda]

hey guys,
i just downloaded yakarov79's AV-8B Harrier II and it looks like its missing the gun..
the loadout screen shows it greyed out saying 'this aircraft is not equipped with an internal gun' but it should have.
i downloaded and extracted all 4 parts and put everything where it should.
the folder /StrikeFighters2/Objects/Guns/25MM_GAU12AIR is present with both .ini files so i don't know what is missing..

i know i'm too many years too late but i just find out about the game so i have to catch up!

also, how am i supposed to use the ARBS?

thanks