"The release notes proper are here:
https://github.com/diydrones/MissionPlanner/blob/master/ChangeLog.txt"

"I have an issue in which the APM 2 will not arm, and the red (A) led is blinking twice fast. It seem like there must be a list of error status codes somewhere, but I've not  been able to find.

Does anyone know where a more thorough explanation of…"

"I have the same trouble with a new unflown board, no dataflash, no compass, and the onboard sensors are not working. I just uploaded the latest 3.0 rc-1 firmware and there is now some additional output now instead of just hanging on "Init Gyros"…"