Compass variance

I cant calibrate my compass for some reason. I have a rpi 2b and navio+ i connect to mission planner via ethernet. When i try to calibrate i follow the instuctions but i still get huge offsets i get 2.5 error level. Then mission planner also displays “error compass variance”. I have read in the forum that alot of people had this problem but i never found a solution
Please help


Try to put your rpi2/Navio+ away from power distribution/ESC/Battery.
I have the exact same problem, you need to look at offsets after calibration, if the value are far from 0/400/-400 you probably have interferences.
Prefere aluminium and plastic or Carbon for your frame and avoid metalic stuff.