caliberatate results in an "Nan" error

[jaxkingdom]

I caliberatate my mpu9250, it's result as follows, but when run kalman by .json file, the yawl info return Nan,why? %Run complete_caliberation.py Accel calibration starting Acceleration calibration is starting and keep placing the IMU in 6 different directions based on the instructions below Put the IMU in 1 position. Press enter to continue.. [-0.28412242 1.1355439 10.50506506] [] [] [10.505065058365755] Put the IMU in 2 position. Press enter to continue.. [ 1.13468195 -1.13422702 -8.98501074] [] [] [10.505065058365755, -8.985010735637445] Put the IMU in 3 position. Press enter to continue.. [ 0.5851727 -9.76096913 1.58245638] [] [-9.760969127946899] [10.505065058365755, -8.985010735637445] Put the IMU in 4 position. Press enter to continue.. [-0.30771249 9.53003063 -0.44961807] [] [-9.760969127946899, 9.53003062668803] [10.505065058365755, -8.985010735637445] Put the IMU in 5 position. Press enter to continue.. [-9.43546681 -0.34059852 0.18578156] [-9.435466814373997] [-9.760969127946899, 9.53003062668803] [10.505065058365755, -8.985010735637445] Put the IMU in 6 position. Press enter to continue.. [9.90379053 0.32024079 1.38590037] [-9.435466814373997, 9.903790533302814] [-9.760969127946899, 9.53003062668803] [10.505065058365755, -8.985010735637445] Accel calibration Finisehd [ 0.23748847 -0.11740262 0.76485966] [1.01420647 1.01674357 1.00635832] Mag calibration starting /usr/local/lib/python3.7/dist-packages/imusensor-1.0.1-py3.7.egg/imusensor/MPU9250/MPU9250.py:400: RuntimeWarning: invalid value encountered in double_scalars Mag calibration Finished [-4.11800666 25.14775067 5.39850273] [[nan nan nan] [nan nan nan] [nan nan nan]] [1. 1. 1.]