I had a base defence mission pop up. I immediately aborted, and the game crashed with a seg fault. I have no idea if it's openXcom, CE, or TwoTS, so please pass it up the chain to whichever project if/as applicable.
Attached save reproduces it. TwoTS 2.5. From the log:
[11-10-2021_15-09-42] [WARN] No free channels available
[11-10-2021_15-11-01] [FATAL] A fatal error has occurred: Segmentation fault.
[11-10-2021_15-11-01] [FATAL] 0x5b6360 OpenXcom::CrossPlatform::stackTrace(void*)
[11-10-2021_15-11-01] [FATAL] 0x5b71e0 OpenXcom::CrossPlatform::crashDump(void*, std::__cxx11::basic_string<char, std::char_traits<char>, std::allocator<char> > const&)
[11-10-2021_15-11-01] [FATAL] 0x41c7f0 signalLogger(int)
[11-10-2021_15-11-01] [FATAL] 0x9c1bc0 OpenXcom::UfopaediaStartState::think()
[11-10-2021_15-11-01] [FATAL] 0x76e078bc _C_specific_handler
[11-10-2021_15-11-01] [FATAL] 0x76e18080 RtlDecodePointer
[11-10-2021_15-11-01] [FATAL] 0x76e079a0 RtlUnwindEx
[11-10-2021_15-11-01] [FATAL] 0x76e3bc8a KiUserExceptionDispatcher
[11-10-2021_15-11-01] [FATAL] 0x510730 OpenXcom::BattlescapeState::resetUiButton()
[11-10-2021_15-11-01] [FATAL] 0x4f0430 OpenXcom::BattlescapeGame::convertUnit(OpenXcom::BattleUnit*)
[11-10-2021_15-11-01] [FATAL] 0x5366a0 OpenXcom::DebriefingState::prepareDebriefing()
[11-10-2021_15-11-01] [FATAL] 0x53c090 OpenXcom::DebriefingState::init()
[11-10-2021_15-11-01] [FATAL] 0x5ce5b0 OpenXcom::Game::run()
[11-10-2021_15-11-01] [FATAL] 0x41c950 SDL_main
[11-10-2021_15-11-01] [FATAL] 0x9c36f0 console_main
[11-10-2021_15-11-01] [FATAL] 0x9c3810 WinMain
[11-10-2021_15-11-01] [FATAL] ??
[11-10-2021_15-11-01] [FATAL] ??
[11-10-2021_15-11-01] [FATAL] 0x76ce59c0 BaseThreadInitThunk
[11-10-2021_15-11-01] [FATAL] 0x76e1a540 RtlUserThreadStart
[11-10-2021_15-12-38] [FATAL] OpenXcom has crashed: Segmentation fault.