Upgrade from 2.74b

Currently flying 2.74b on a Skywalker 1680…no airspeed sensor and I dont do autoland yet…
is there any catastrophic bug in 2.74b that would force me to move to 2.76? being a newbee to Arduplane, I would like to keep changes to one at a time while I learn the system capabilities…

thanks

PS wish it had a simple relative geofence

moved to 2.77 to get arming with rudder