Apparently some Mavic PRO units are coming with interference-sensitive compass 2, the warranty is solving this problem by replacing Gimbal or Compass 2. The real problem is that some parts of the Mavic are magnetized, preventing the Compass calibration process from being completed.

there is a tool called cfixer that solves the problem, but it is very expensive.

So what I did was buy a tool demagnetizer and used it on all the front metal parts of the drone

https://www.banggood.com/Magnetizer-Demagnetizer-Box-Screwdriver-Tips-Screw-Bits-Magnetic-Tool-p-961755.html?rmmds=search&cur_warehouse=CN

Then I reinstalled the last firmware calibrated IMU and COMPASS and now no error message appears, even the Mavic is much less sensitive to external interference.

f my tip does not work for you, try this little tutorial sometimes, some friends with this problem had to try 2 or 3 times to calibrate the drone correctly.

Hi, there. For new users, we would not recommend they modified the drones. Thanks for your understanding.

hi pm me the tutorial

DJI Elektra Posted at 2018-2-10 20:01
Hi, there. For new users, we would not recommend they modified the drones. Thanks for your understanding.

The tool suggested should not in anyway modify drones.  It basically is a Degaussing tool.  Producing a alternative magnetic field that is slowly reduced in strength.  

Hi! Can you tell me how did you do this? Thank you!