This thread is a repeat post of one I started in the General Discussion. I am repeating here because I believe that it is a confirmed bug. In 4.37, the Harrier seems to have no bleed pressure to the axis control nozzles. When flown referencing the DED INS display, one can see this clearly as you slow below 30 knots. Faster than that you have very weak control but still some. Slower and control degrades to nil, best observed in yaw. That DAT files between 4.36 and 4.37 are essentially identical but 4.37 does add an AI Max AOA in the “AOA and Sideslip Limits” section, line 24.
The best confirmation is to test the single AV8B+ in the WASP TE with zero loadout and 5000 lbs. 4.36 demonstrates very good controllability and responsiveness where 4.37 has none of either. At speeds above 80 or so, both versions seem close, if not identical. Moving the .dat files from 4.36 to 4.37 and adding the max AI AOA value of +25.000000 (to avoid a CTD) yields a model that is unchanged from the original 4.37.