This usually happens when Windows headers or the typedef in common.h aren’t being included in the order the code expects. A couple things you can try that often fix the “missing ‘;’ before identifier” error with pthread_mutex_t on older MSVC builds: Make sure <windows.h> is included before common.h. Since pthread_mutex_t is typedef’d as a HANDLE, the compiler needs the Windows types first, otherwise MSVC sees an undefined type and throws that error.</windows.h> Check that you’re using the correct...