Help understanding why RTL was triggered in auto

I have built a new wing that I can use for mapping. I ran my first auto mission today but can figure out why RTL was triggered half way through.

I dont think it was a radio failsafe.

If anyone can help that would be great!

https://drive.google.com/open?id=0B9a6hLvyAT_leUdYM09HSlBKZW8

Never mind i figured it out. How do I delete my post?