magnetometer calibration shows NaN

[RalphKai]

I try to calibrate my Razor IMU M0(SEN 14001)
After closing Processing GUI, it comes out three lines.
In my case, it shows:
boolean CALIBRATION__MAGN_USE_EXTENDED = true; float magn_ellipsoid_center[3] = {528.455, -1481.73, -202.037}; float magn_ellipsoid_transform[3][3] = {{NaN, NaN, NaN}, {NaN, NaN, NaN}, {NaN, NaN, NaN}};

it's strange that magn_ellipsoid_transform get NaN,
Can anyone give me some suggestions, thanks a lot.