I decided to start a thread to see exactly which users have experienced issues when upgrading to P3P Firmware 1.2.6. We know DJI monitors these boards. I am going to do one better and send this thread to the all star team at DJI. These issues include some or all of the following: Ultrasonic System Error: Please Land As Soon As Possible Vertical drifting ascending and descending, while off stick Instability/Inability to hold GPS lock Erratic flying behavior Toilet bowling Shaking Some people have been asking if they should upgrade from 1.1.9 (No, duh). Some have accused that this is a completely isolated incident experienced by an insignificant number of us. I believe that to be completely untrue, and am committed to forcing DJI to take accountability. It is well within the capability of a billion dollar company to empower their customer service employees to send out a firmware file that can revert or reinstall the current firmware revision, at their discretion, to negatively affected customers. By not doing so they are directly responsible for damage to our Phantoms, people, and property when these quads start wrecking due to this software issue. Please, if you are someone who has experienced performance issues after switching to 1.2.6, drop a quick line and chime in. Let's let our voice be heard.