Check the "Command" dates, versus the Base dates, versus the Type IIB dates. I thought we had done a "fix" for that, but it probably did not go out in time for the v6 mix. Specifically, the Command (ID=30Flotilla") has
AvailabilityInterval=1942-09-21, 1944-09-01
While the base Constanza has
AvailabilityInterval= NULL, 1944-08-25 pre-dating the Command
and the Type IIB submarine has
AvailabilityInterval= NULL, NULL
In effect, what happens, is that the boat with the NULL, NULL follows the Base date of 1944-08-25 and is terminated then. However, since you are still assigned to "30Flotilla" (the ID line) for the actual Command, you then are in need of a Submarine with which to patrol in, so the game, out of the kindness of its heart, grants you a new one... even though it is an inappropriate assignment and there is no base from which to sail again, the game did in fact, give it to you, and has therefore "done its job". So what if it causes a CTD? meh
To "fix" it, try the Base itself as a NULL, NULL also, so that both the boat and the base follow the Availability of the 30Flotilla Command... maybe...
- If that does not work, then change the date of the 30Flotilla to
1942-09-21, 1944-08-24, a day earlier than the Base's demise... I am almost positive though, that the "fix" was to do the NULL, NULL... ??