After having used an other controller I purchased recently an Ikarus controller for Aerofly RC8 and couldn't configure it properly on my Imac. I tried different things like changing the settings or deleting and reloading the app without result. Finally I found that I had to delete not only the app but also the associated files. The free app AppCleaner can do that. Then I reinstalled RC 8 and everything was fine. This may help others.