Ok... Calibrated the compass earlier today at the local AMA airfield. Flew without incident. Mod values were around 1500 no wobble or toilet bowl not a thing. Flew 4 batteries went home charged up the batteries after they cooled for a few hours and headed out. Went to a new location flew a few minutes and realized that the ND filter was too dark so I brought the copter down switched off the copter took the ND filter off switched the copter back on and lifted off. You will see that it says take-off battery 65% or something close but truly I took off on a full battery the first portion of the flight landed made the adjustment and took off. Still I monitored the voltage and noted no issues. Truly none. Well I'm flying getting ready to make a run toward a water tank which at that point was more than 1000 meters away... then I get a big RED: COMPASS ERROR indicator where my warm and fuzzy green box is supposed to be....NO BUENO.. Boom "remembering my training"... HAHA.. Young Padawon... I quickly switched to ATTI mode and flew directly home. I got it to about 5 feet off the deck and a few feet away. I switched back to GPS grabbed it and shut it down. I swapped in a new battery and launched again. I checked the sensors and noticed no issues..No drift.. No toilet bowl no wobble nothing.. I let the battery warmup and flew again without a single problem.. WTH happened. Anyway I thought I would ask some of the Phantaholics on here to have a look at the Healthy Drone link.. I looked at the flight on healthydrones and saw nothing related to the compass. Is it common to get these errors? I was flying in an absolutely vacant lot. No real problems with interference. I have flown before without incident. Anyway take a look at the flight and let me know if I did something wrong. HealthyDrones.com - Innovative flight data analysis that matters Do I need to get the other file? I'm not sure how I do that.. Any help on the diagnosis and instruction on how to pull the files needed would be great.. Thanks Phantaholics.