LG G3 Download mode blocked by kill switch.

[AC Question]

Hey everybody, I've been trying to root my lg g3 for the last couple of days and haven't had any luck. When ever I try to root or put my phone into download mode I get a message that says "download mode blocked by kill switch". I've been looking all over the internet and forums but haven't been able to find a solution. My phone is a lg g3 unlocked AT&T, running android 5.0.1. Any suggestions would be great!