which ENB are you using? what happens if you remove sweetfx and replace it with ENB?
i use 0.75 version and it just crash to desktop when click the WOFF application
ENB should not cause the WOFF manager to crash to desktop as it is not loaded at that time. ENB will run once you click on start mission and the CFS3.exe gets loaded. Then, if you crash, it will go back to the WOFF manager and usually you'll see a "dll" error message window.
EDIT: Two things I am guessing that is happening is that you are overwritting the sweetfx with enb or AnKor's shadow mod is not set up correctly.
Also, you can try to reinstall the full directx package.