I have found the addon, it is XA snow, when I deactivate it, x-plane no longer crashes. However, all other planes do not react like this.
I have a question about the Islander, since the manual is more than poor, I can't find a way to assign the reverse or beta function to my Bravo throttle quadrant by command. I have tried it with ‘beta’, also with ‘toggle thrust reversers’, without getting a reaction. Which command would make this possible? But I can't trigger this with the mouse either. So how does the reverse position work?