Dllmain XTrap Error

#include <windows.h>

BOOL WINAPI DllMain(HMODULE hDll, DWORD dwReason, LPVOID lpReserved)
{
       if (dwReason == DLL_PROCESS_ATTACH)
       {
              DisableThreadLibraryCalls(hDll);
              MessageBoxA(NULL,"Test","Test",NULL);
       }
       return TRUE;
}