My Mavic has flown flawlessly since I got it in December last year. Over the last few weeks I get a compass error saying move the aircraft position or re calibrate the compass. This can happen several times during the flight. The compass was calibrated before I flew and it happens at two of my main flying sites. There is no metal around. I see the status light flashing green and yellow when this happens. It occurs most often when I open the throttle up. It displays briefly on the screen, but is not recorded in the warnings. It does not seem to affect its flight. I am on the latest Android  DJI Go 4 App and firmware. It has never been crashed or a hard landing. I am reluctant to send it back with summer approaching. Advice would be appreciated on thoughts whether this is a bug or an underlying problem. Apart from this, I love the Mavic!

Given that your Mavic was an early model it's likely that this thread is relevant to your problem. If you'd like a more definitive diagnosis then please provide a link to a DAT file from a flight where this happened. The DAT file is stored on your Mavic and can be retrieved using these instructions, after which you'll need to store the file in DropBox and provide a link to it in this thread.

DroneFlying Posted at 2017-6-5 13:26
Given that your Mavic was an early model it's likely that this thread is relevant to your problem. If you'd like a more definitive diagnosis then please provide a link to a DAT file from a flight where this happened. The DAT file is stored on your Mavic and can be retrieved using these instructions, after which you'll need to store the file in DropBox and provide a link to it in this thread.

Many thanks for your reply. I had a look at your thread link. This could well be my issue. I will try uploading the .dat file. Iain

Compass errors and Cell Data are weird This thread is probably the #1. Most confusing issue for me. And they way I look at it, is that Unlike other Drone the Mavic Controller is Far Superior since it has its Own display. And You NEVER Ever need Cellphone Service to Fly. The Cellphone there is Just an Extra Display. However IN my humble option Cell Phone Service LTE Data is DJI's Ulterior Motive in that people think they need Cell Service or LTE Data is there way of Registering each flight with the FAA, just yesterday there was a thread that a person Could NOT fly Unless there was a CHINA based phone number Registered to the account. That did Not mean LTE Cell Service is neeeded to Fly. I Personally Do a Pre-flight Update at home On WiFi. Then Switch to Airplane Mode On my cellphone because who wants to get a call during flight or Have a Game Start an Update while flying ?