Rooting the Motoroloa Droid 4 with Build Version 9.8.20-72_VZW-18
I just rooted my Motoroloa Droid 4 that was running build version 9.8.20-72_VZW-18 and had a couple of problems so I wanted to post the solution up here.
So, the current exploit you will find pretty much everywhere is the Motorola Droid Razr 4.1 Root Exploit. When I tried to run this it completed but didn't grant me root. The problem is that the script doesn't wait long enough for the phone to enter Low Battery Saver mode (the script calls this "Battery Saver" mode, but it has been renamed) so the exploit doesn't end up working. There are two things you can do to fix this:
1) Enter each line you see in the script by hand. When you see lines like `adb shell "sleep 5"` don't execute those lines. Instead, just wait about a minute before continuing.
2) Edit the razr_blade.sh file and replace the "sleep 5" line with "sleep 60" and the "sleep 40" line with "sleep 120". This is a bit overkill but should do the trick.
This should allow you to root your phone.