Hi, yes it was the "AI_Uboats_v2.0" mod, I didn't use JSGME as it flattens 2 files: "NSS_Uboat2B_shp.tga" & "NSS_Uboat7c41_shp.tga"! so I just copied the mod to the data folder, anyway I had the original GW data folder saved so was able to fix, all of the mods are back in except the AI U-Boats mod & all works fine.
Thanks all.