Copter nearly crashed

Hello,
can someone help me to interpret the log.
Arducopter 3.4.4
auav-x2
https://drive.google.com/file/d/0BxeHasQUHjS1aXZGblFKMW5zOEk/view?usp=sharing

I disabled the 2nd compass, becourse after update to 3.4.4 it is’t calibrating good. (always red or yellow values)

The i flyed and in Loiter i got nearly a crash.
HDOP was good.

Thanks a lot.

Regards a.

I can’t access the log.Did you fly in stabilize first to teach it the hover value ? You have to hover it,switch into alt hold and then back to stabilize. and raise the throttle to hover again.Once you’ve done that it should learn throttle mid.You’ll have to chack but I think you need to do that each flight unless you’ve enabled learn and save in the parameters.

2017-02-19 15-40-04.bin (3.3 MB)

Hello, here is the logfile.
Thanks a lot.

Made a onbord compass calibration with relaxed settings.
Now no prearm compass failure.

Do i have to do compass mot again?

Thanks!

BR Anton