Tried to test motor today and I cannot arm.
FC is pixracer.
Plase provide a dataflash log (use LOG_DISARMED).
Its a bit confusing as the subject here specifies both stable and unstable
versions 
Steps to reproduce would also be good.
I have flying wing, bn-880, compass disabled, nothinf special.
I put model on bench to check motor, try to arm via radio and I saw this error.
Firmwate is latest from today.
Then I have confusing part, I enabled diasmed log and I see error EKF3 or 2 not started. (disabling log didn’t help).
What I have are logs from EKFs not started https://www.dropbox.com/sh/sky5rm2c8crbejy/AADPaTenhy7RzRNHvWc6sIGZa?dl=0
And video with original error https://youtu.be/bXmOPp7SuBI
Today I tried again, I reinstalled from scratch and same error EKF3 not started.