Openapoc: Battleship won't selfdestruct/May be preventing save

Quick update: I was able to get the error only hours after the mission. You don't have to wait until the next day. However, the game did let me save immediately after loading the save the first time.

Another update: I believe firmly now that the UFO not self destructing is preventing the game from completing a save. I was able to save the game originally because time had been paused and the code to self destruct had not been ran so the UFO was legitimately still there. However, since the UFO DIDN'T self destruct, something is going wrong in the code when the game tries to save.

W 12605447300 void __cdecl OpenApoc::GameState::validate(void): Validating GameState
W 12614002600 void __cdecl OpenApoc::GameState::validate(void): Validated GameState
W 105548142800 void __cdecl OpenApoc::GameState::validate(void): Validating GameState
W 105555531100 void __cdecl OpenApoc::GameState::validate(void): Validated GameState
E 154428341400 void __cdecl OpenApoc::serializeOut(class OpenApoc::SerializationNode *,const enum OpenApoc::VehicleMission::MissionType &,const enum OpenApoc::VehicleMission::MissionType &,const class std::map,class std::allocator > > &): Invalid enum value for enum OpenApoc::VehicleMission::MissionType: 6
0x00007FF70EAB998A PHYSFS_writeSLE64+0x1cb26a
0x00007FF70EB15DFD PHYSFS_writeSLE64+0x2276dd
0x00007FF70EB0FD5D PHYSFS_writeSLE64+0x22163d
0x00007FF70EAA5F6C PHYSFS_writeSLE64+0x1b784c
0x00007FF70EB0EE42 PHYSFS_writeSLE64+0x220722
0x00007FF70EAB2A48 PHYSFS_writeSLE64+0x1c4328
0x00007FF70EB05E7E PHYSFS_writeSLE64+0x21775e
0x00007FF70E91A73F PHYSFS_writeSLE64+0x2c01f
0x00007FF70EA3922B PHYSFS_writeSLE64+0x14ab0b
0x00007FF70EA38703 PHYSFS_writeSLE64+0x149fe3
0x00007FF70E7FD2E9 PHYSFS_writeSLE64+0xfffffffffff0ebc9
0x00007FF70E833BB0 PHYSFS_writeSLE64+0xfffffffffff45490
0x00007FF70E706DDA PHYSFS_writeSLE64+0xffffffffffe186ba
0x00007FF70E707663 PHYSFS_writeSLE64+0xffffffffffe18f43
0x00007FF70E6E1032 PHYSFS_writeSLE64+0xffffffffffdf2912
0x00007FF70EB9BDA5 PHYSFS_writeSLE64+0x2ad685
0x00007FF70E8EF135 PHYSFS_writeSLE64+0xa15
0x00007FF8BD6D7974 BaseThreadInitThunk+0x14
0x00007FF8BDE3A271 RtlUserThreadStart+0x21

Perhaps final update: Using ctrl+shift+alt+right-click destroyed the UFO and again allowed saving.

The fix above probably won't solve this - but hopefully fix the saving, so we can get a better reproduction case?

UFO self-destruction after a battle is fixed in #878.