Here is message from my dealer. I tie rap my sensor like he recommanded and never had problem again.
"In my opinion, there will be some kind of problem that one of the many sensors is finding.
For example- If you reduce throttle very quickly and decent rapidly one of the exhaust gas sensors will be colder than the other and the engine computer registers it as a problem with the sensor failing due to the large variance in temperatures.
There could be a fuel pressure issue, an electrical connection issue on any of the many sensors. It is very difficult to guess what is setting off the alarm without the use of the Rotax dongle.
The “Land Aircraft” alert is a general alarm for any one of many problems with any of the engine hardware/sensors that could occur.
First thing to do is Try the “ty-wrap trick" the same as the photo below. That may fix your problem just by adding some support to the wiring connection.