Ha, I fell into the exact same trap.
I didn't want anything that changed the game's mechanics. So I installed only what I thought were basic mods. Extra explosions, vanilla UFO variants, expanded Ubase reworked, terrain pack. I thought I was mostly just getting more variety in Battlescape layouts. But that last one put an Antarctica base into ocean water, and bugged the bases' location string in the base screen. I thought oh well, whatever, but eventually UFOs sometimes crashed the game with segmentation fault when they got shot down. And then the game would crash upon reaching June 1, also with segmentation fault like OP.
Interestingly, stripping all mods EXCEPT the terrain pack and/or dismantling the Antarctica base also crashed the game, but with a better message: "Error processing mission script named: recon, region named: STR_PACIFIC is not defined".
Stripping the terrain pack as well lets the game continue between months but crashes at random but replicable points such as seconds after June 7 23:02 with yet another error message:
[25-01-2020_15-01-10] [FATAL] A fatal error has occurred: vector::_M_range_check: __n (which is 3) >= this->size() (which is 2)
[25-01-2020_15-01-11] [FATAL] 0x645ab0 OpenXcom::CrossPlatform::stackTrace(void*)
[25-01-2020_15-01-11] [FATAL] 0x649380 OpenXcom::CrossPlatform::crashDump(void*, std::__cxx11::basic_string<char, std::char_traits<char>, std::allocator<char> > const&)
[25-01-2020_15-01-11] [FATAL] 0x401580 exceptionLogger()
[25-01-2020_15-01-11] [FATAL] 0xa38dd8 MPEGaction::MPEGaction()
[25-01-2020_15-01-11] [FATAL] 0x7ee360 OpenXcom::AlienMission::getWaypoint(OpenXcom::UfoTrajectory const&, unsigned int, OpenXcom::Globe const&, OpenXcom::RuleRegion const&)
[25-01-2020_15-01-11] [FATAL] 0x7f3930 OpenXcom::AlienMission::ufoReachedWaypoint(OpenXcom::Ufo&, OpenXcom::Game&, OpenXcom::Globe const&)
[25-01-2020_15-01-11] [FATAL] 0x43f0d0 OpenXcom::GeoscapeState::time5Seconds()
[25-01-2020_15-01-11] [FATAL] 0x452080 OpenXcom::GeoscapeState::timeAdvance()
[25-01-2020_15-01-11] [FATAL] 0x642d30 OpenXcom::Timer::think(OpenXcom::State*, OpenXcom::Surface*)
[25-01-2020_15-01-11] [FATAL] 0x452cb0 OpenXcom::GeoscapeState::think()
[25-01-2020_15-01-11] [FATAL] 0x64c3d0 OpenXcom::Game::run()
[25-01-2020_15-01-11] [FATAL] 0x401820 SDL_main
[25-01-2020_15-01-11] [FATAL] 0x87df00 console_main
[25-01-2020_15-01-11] [FATAL] ??
[25-01-2020_15-01-11] [FATAL] 0x767b0400 BaseThreadInitThunk
[25-01-2020_15-01-11] [FATAL] 0x77126540 RtlGetAppContainerNamedObjectPath
[25-01-2020_15-01-11] [FATAL] 0x77126540 RtlGetAppContainerNamedObjectPath
So as it happens I can keep the game running by turning the mod on at some points and off at some other points, in time. Not that I care about this save file, I was gonna start another game anyway. But yah, lesson learned. Don't underestimate a mod's ability to conflict with the base game or other mods!