How can I overcome this problem?
Devices:
Samsung Galaxy TabS - Android 4.4.2
HTC M8 - Android 5.0.1
The two devices have the same problem.
Your device is not rooted. To see what Rooting is and how to go about doing it:
Once you have rooted your device, you will be able to access the Super User state of your device (SU). Just be aware that rooting could brick your device if done incorrectly, as could and tampering with files in the root directory.
su
binary doesn't come with factory shipped devices. You need to root the device (which involves finding and pushing thesu
binary into/system/bin/
or/system/xbin/
). See What is rooting? – Firelord Nov 03 '15 at 12:14su
and in order to accesssu
it has to be present first. How would you move the binary depends upon the device you're using. Some methods are mentioned here: How do I root my Android device? – Firelord Nov 03 '15 at 12:26