I am pretty sure you need to be running as lot to change SELinux in this manner which I'm guessing is what you're trying to get in the first place.
Chances are you need to run a different exploit on your device to obtain root
Looks like a Samsung device judging by the font, but would need to know more info to point you in the proper direction such as make, model, android version, carrier etc
Just saw your signature and it appears you have a version branded S4, depending on the version this guide should help you out
Let me know if you have further questions