Okay and thank you for your quick response.
So here's the full story: I drove down the battery to 2% and went to a DC Charger. After about 45' I stoped the charging with the station, not the bike. An error quickly popped up which I couldn't read so fast and the yellow engine symbol on the right hand side appeared and stayed. I started the ride home and while overtaking a car with full throttle the engine suddenly stopped and displayed a red triangle with an "!" and an "undefined error, call service center" message. I pulled over and tried several times off an on switching, but the failure stayed. I could not engage the GO mode anymore. I left the bike switched on for the hazard lights and organised a towaway service. After a while the bike switched off by itself and when I switched it on again, the red warnings were gone and I was able to drive again. Still with the yellow engine symbol on the right side of the display. I drove home very carefully in rain mode for more than 1 hour with normal speed.
When I was close to home I went to a DC fastcharger again and charged the bike for 5 minutes. After that I stopped the charging from the bike and all the warnings and symbols have been cleared!!!
The day after, when I switched on the bike again in the garage, all the warnings came back.
Sorry, it's a bit long but I know the details help.
Kind regards to all of you