Havent flown in a while and during last flight did not crash.  Put drone away and was able to finally update P3P to v1.8.  Had no problem updating P3 and controller but then got error message of MC DATA ERROR, ACCELEROMETER FAILURE.  I searched the forums and found that this was an issue after a crash and to re-calibrate the IMU.  Tried to re-calibrate the IMU but got UNKNOWN ERROR message.  Noticed that Acceleration was way off at -16 so I figured if the "acceleration" (moving forward value) was off and remebering what I saw in other forum posts about giving the Phantom a "wack" on opposite side of crash I decided to "wack" it in the front.  Went to re-calibrate and immeiately saw that value was up to -1 and then zeroed out after successful IMU calibration.  Everyting in the green now.  Like I said I havent crashed it, this happended after the update so what gives DJI?  

Hello jg18970, normally the IMU calibration failure is a hardware issue. But if it comes up after firmware upgrading, I'd suggest you to try to upgrade the firmware again.If the re-upgrading keeps failed, feel free to post the hidden log here.