I just got my MacBook Pro updated to OS X El Capitan and ran into problem with the system level utilities that I use for my work. They are now barred in El Capitan and you can no more access them. But thankfully there is an easy fix to this problem as mentioned below:
Restart your computer into recovery mode by holding down ⌘ + R until Apple logo appears on the screen
Click Utilities > Terminal
In the terminal type csrutil disable
Reboot the computer
Voila! You are done. To enable again follow the same procedure and just type csrutil enable
Hope you will find this small tip useful.