Are you using the v1.5 of SH4? You need to have German U-Boats available in the game. It might also be name "Gold Edition". If you are using the Steam version of the game, be certain you are using the correct Steam short-cut to start the game. Wolves of the Pacific gets you v1.3, whereas U-Boat Missions gets you v1.5... You to still play the US Pacific side in v1.5, but a German career is also available. Also, DirectX v9.0c must also be installed so that the DirectX on your computer includes the old "calls" for the old game...
