To reproduce crash create a pit/pond zone anywhere on the map and click the button to select an entity to pit and the game crash.

Game version : v50.12-beta21

Crashlog :
0> Dwarf_Fortress!std::_Init_locks::operator=+0x80A956
1> Dwarf_Fortress!std::_Init_locks::operator=+0x80AAC9
2> KERNELBASE!UnhandledExceptionFilter+0x1EC
3> ntdll!memcpy+0x2BBD
4> ntdll!_C_specific_handler+0x97
5> ntdll!_chkstk+0x12F
6> ntdll!RtlFindCharInUnicodeString+0xA96
7> ntdll!KiUserExceptionDispatcher+0x2E
8> Dwarf_Fortress!std::_Init_locks::operator=+0x2D4AA9
9> Dwarf_Fortress!std::_Init_locks::operator=+0x2B2A5E
10> Dwarf_Fortress!std::_Init_locks::operator=+0x2DF61F
11> Dwarf_Fortress!std::_Init_locks::operator=+0x104ADB3
12> Dwarf_Fortress!std::_Init_locks::operator=+0x104C318
13> Dwarf_Fortress!std::_Init_locks::operator=+0x2B176F
14> Dwarf_Fortress!std::_Init_locks::operator=+0x2589C8
15> Dwarf_Fortress!std::_Init_locks::operator=+0x617D28
16> Dwarf_Fortress!std::_Init_locks::operator=+0x9133BB
17> Dwarf_Fortress!std::_Init_locks::operator=+0x63D764
18> Dwarf_Fortress!std::_Init_locks::operator=+0x63EB19
19> SDL2!SDL_DYNAPI_entry+0x799D7
20> SDL2!SDL_DYNAPI_entry+0x12EEDE
21> ucrtbase!recalloc+0xA3
22> KERNEL32!BaseThreadInitThunk+0x1D
23> ntdll!RtlUserThreadStart+0x28