To repair your PIN & picture password:
Open File Explorer and browse to this location:
C:\Windows\ServiceProfiles\LocalService\AppData\Lo cal\Microsoft\NGC
Delete everything within that folder
Go to Settings-> Accounts->Sign-in Options
Click Add a PIN again and set your PIN
PIN sign in should work going forward

Kurz auf Deutsch:

"C:\Windows\ServiceProfiles\LocalService\AppData\L o cal\Microsoft\NGC " öffnen und den dort enthaltenen Ordner löschen.