PPSSPP crashed after changing backend to Direct3d11

[kvintanzil]

as the title said, i just installed the latest build of PPSSPP (v1.4.2) and when i launch the app it worked fine but the first thing i do is changing the backend from openGL to direct3d11 and it crashed right after i apply it, now i can't open the application at all because it always crash, both the 32 and 64 bit version. how do i fix this? i can't even change it back to openGL backend because it won't let me go into setting before it crash and there's no memstick folder in the install directory, i've tried uninstalling and reinstall the app but the app still crash, help!