X11DRV_WindowMessage handle WM_X11DRV_SET_CURSOR message will owner win_data_section and wait loader_section(call stack set_window_cursor ->create_cursor->create_xcursor_system_cursor->GetModuleHandleW), if load FlashControl.dll in other thread(thread B), thread B will CreateWindow in process_attach entry, so in thread B owner loader_section and wait win_data_section. This situation will caused deadlocked