I got only once as schwarzfahren because I had forgot my pocket money with everything.
then the controller took my data and gave me the fine which I payed directly next day in the office.
then after a week I got a letter from the police as I did not pay, However I called them and they were so helpful and told me to sent the receipt that I payed the fine and they will close the case.
after a while I had a letter from the city attorny that I had no case.
So do you think that would cause any problems in the future
How to fix it if possible and If I wanted to renew my residence permit after 2 years would they reject if I moved to another city