Getting this crash sometimes when flipping the overflow valve horizontally
ERROR: SymGetLineFromAddr64, GetLastError: 487 (Address: 00007FF8B2687374)
00007FF8B2687374 (KERNEL32): (filename not available): BaseThreadInitThunk
ERROR: SymGetLineFromAddr64, GetLastError: 487 (Address: 00007FF8B413CC91)
00007FF8B413CC91 (ntdll): (filename not available): RtlUserThreadStart
Stack trace logging done
167.649 Error Entity.cpp:2305: flipResult.direction != Direction::None was not true
167.649 Error CrashHandler.cpp:643: Received 22
Logger::writeStacktrace skipped.
167.649 Error CrashHandler.cpp:190: Map tick at moment of crash: 251977510
167.713 Info CrashHandler.cpp:318: Executable CRC: 1465241209
167.713 Error Util.cpp:95: Unexpected error occurred. If you're running the latest version of the game you can help us solve the problem by posting the contents of the log file on the Factorio forums.
Please also include the save file(s), any mods you may be using, and any steps you know of to reproduce the crash.
170.985 Uploading log file
171.004 Error CrashHandler.cpp:270: Heap validation: success.
171.005 Creating crash dump.
171.196 CrashDump success

Hello! Thanks for the report! This is an Factorio engine bug so I can't fix it unfortunately. There's already an open discussion here. If you want you can make a post on the forums here that you also ran into this crash.