Experiencing IMU calibration issue on start up after a change of battery or a restart...will not let me start the drone and continualy states "IMU calibrating, please wait until calibration is complete". However, it never gets complete....I am not experiencing the issue on a fresh start up. Please assist in resolving the issue.

Four hours and nobody has responded to your thread.

Your post is confusing.  It sounds like you're doing an IMU calibration in the field?  That's unusual.  

At any rate, sounds like the system crashed.  So I'd turn it off, wait a few secs, turn it back on and watch that it boots correctly.  Then turn it off.  Go home.  Go to a desktop to do your IMU calibration.  Be sure Phantom is perfectly level before you start.  See your manual for more details.  

IMU calibration should be on a flat level surface free of vibration.  Even free from vibration of walking around.  It should best be done on a cool drone and battery and immediately after turning power on.  And read the manual as the above poster mentioned.  :-)

I have same problem..

I have same issue, stop here in never go

Just to make sure I'm on the same page, you did not initiate the IMU calibration process, correct? Did you notice this happening after a firmware update, app update, or a hard landing? What mobile device, firmware and app version are you running?

Sorry to be negative. but my first Phantom 4 Pro showed IMU errors straight out of the box. It would fly, but continuously said IMU calibration was needed However the calibration procedure always got stuck on screen 1 and the settings menu reported "data error" against ACC0.  I tried all firmware versions. After this I got total IMU cal failure and it refused to fly at all. on day 2 out of the box....

charlesP4P Posted at 2017-5-22 22:27
Sorry to be negative. but my first Phantom 4 Pro showed IMU errors straight out of the box. It would fly, but continuously said IMU calibration was needed However the calibration procedure always got stuck on screen 1 and the settings menu reported "data error" against ACC0.  I tried all firmware versions. After this I got total IMU cal failure and it refused to fly at all. on day 2 out of the box....

Meant to add............  Luckily I paid a bit more to get it from a good retailer (Jessops in the UK) and within 2 working days they had swapped it for a brand new unit which is 100% OK so far