Were you in an S18 or S42 sub by chance?...
mark bonamer found an issue with that mod over in
THEBERBSTEES All In One Beginners Mega Mod List For SH4 221117, starting with that Post #26 there. Apparently, the S18 and 42 boats do not like it when their torpedoes are tweaked. I had the same issue in regular GFO also. You might have to just remove the mod in order to be able to play the game, or don't use the "S" boats...
Another aspect that can contribute to similar issues is if you play a mission in the game that was not written with that particular mod enabled. In other words, the submarine, when it was added into the mission file that you've got, did not have the stronger torpedoes, and now you're playing that mission with a mod where it does have stronger torpedoes. For some reason, the game itself cannot handle those situations. I'm not sure which aspects of the game can't be changed, but we've found troubles like that before...