Check the settings in mylink (could be set to towbar attached if you don't have one etc).
Good way to test the sensors would be to try an automatic park, if it won't let you or just won't activate at all then there is probably something up with the sensors. Maybe try disconnecting the battery for 10 minutes, I read another user had this problem and disconnecting and reconnecting the battery after 10 minutes fixed the problem.
Hope this helps.