J_43

I have been playing around with DCS for a while now, just getting use to it, playing around with the free TF-51D. I had created some missions with the TF-51D no problem. I decided to buy the P-51D module and now when using the mission editor the P-51D and TF-51D are no longer in the dropdown box for "Type" of aircraft. I have the steam version. Appreciate any help, it may well be that I'm just missing something really obvious. Thanks!