“Key Error…try again”

Hello, this morning I wanted to go to work, put the key in the ignition hole, turn the key around – but nothing happens and in the onboard computer the error message “key error-try again” appeared then about 5 times tried, but nothing happened and then drove with my second car into the company … When I just came home I tried again felt 500 times – and at once went again! The car ran… then the key again a bzug, it tried again…and all the crap started over…So if you try it a lot of times…but it’s not normal, does anyone know what that could be???