Ever since new firmware update After about 30 seconds of flight the warning ultrasonic sensor error please land immediately comes up.
I have calibrated compass and imu but still the same. Anyone else having the same problem?

Firmware and app were both updated,

Which firmware and what model phantom are you using?  There have been issues with new firmware  and so you may need to downgrade your firmware.

Tripp Posted at 2018-2-9 20:10
Which firmware and what model phantom are you using?  There have been issues with new firmware  and so you may need to downgrade your firmware.

My app is 4.2.6  my aircraft is 02.00.0700 and controler is 1.9.3.           

Hi there, just to verify, did the drone crash before? Please help to confirm, and please don't mount the third-party accessory on the drone. And try to calibrate the Vision System via DJI Assistant 2, restart the drone for a couple times. If the issue persists, you might need to send the drone in. Please contact our support to start a case. Here’s the link to contact us: http://www.dji.com/support

No crash ever. I go have a gimbal guard on could this be causing the problem?

Farmflyer321 Posted at 2018-2-10 02:01
No crash ever. I go have a gimbal guard on could this be causing the problem? [view_image]

I would remove the gimbal guard before it causes a crash. There are two ultrasonic transducers in the base of the aircraft (one transmitter, one receiver) so that it can accurately measure its height from ground/structure below it.

I would remove that and then do a 'Sensor' calibration using DJI Assistant 2 as DJI Thor suggested, then the aircraft should be a lot happier.

I will try that and see if it fixes the problem. I didnt have the problem before firmware update even with the gimbal  guard on, but i will remove it and recalibrate and see how i go.
Thanks for the tips.

Farmflyer321 Posted at 2018-2-10 02:18
I will try that and see if it fixes the problem. I didnt have the problem before firmware update even with the gimbal  guard on, but i will remove it and recalibrate and see how i go.
Thanks for the tips.

"I didnt have the problem before firmware update"

I could be wrong of course (not unknown, just ask my other half), but the guards have definitely caused problems for a number of people in the past. Perhaps with the updated firmware the measurement parameters may have changed. A refresh of the firmware and factory reset may be worth a try as well, if calibration etc doesn't work.

Success i removed gimbal guard and calibrated vision positioning and hs seemed to fix all problems. Thanks for your help

Farmflyer321 Posted at 2018-2-10 17:46
Success  i removed gimbal guard and calibrated vision positioning and hs seemed to fix all problems. Thanks for your help

Awesome result glad you got it solved

Farmflyer321 Posted at 2018-2-10 02:01
No crash ever. I go have a gimbal guard on could this be causing the problem? [view_image]

Yes Gimbel guard reflex sonar signal like water does