It looks like the quad was moving then started tipping over before you hit the motor emergency stop.
I cant see the actual cause, but I dont think weak magnetic field will cause that. You would probably benefit from doing the compass/motor calibration anyway.
Someone with more experience than I (and there are many) will need to check the log and see if the cause can be found.
I would probably set FENCE_ENABLE,1 so that you’re forced to wait for a good 3D fix before take-off.
There’s some motor mount twist, CW motors (3 and 4) are working harder to counteract some physical yaw issue with CCW motors (1 and 2). This wont be the cause of the crash, of course, but something to check.
You should set MOT_BAT_VOLT_MIN, MOT_BAT_VOLT_MAX and MOT_THST_EXPO according to the tuning docs
and use this spreadsheet to help https://www.dropbox.com/s/8u9v3ddph6u9u3t/Initial%20parameters.xls?dl=0
You will also benefit from setting up the harmonic notch filter.
Do you have T-Motor Flame ESCs? If so you’ll need to set these:
And then probably run autotune again without a load.
EDIT: and you can set these too: