Non-nullable property 'Kundenname' must contain a non-null value when exiting constructor. Consider adding the 'required' modifier or declaring the property as nullable.

Non-nullable property 'Nummer' must contain a non-null value when exiting constructor. Consider adding the 'required' modifier or declaring the property as nullable.

Non-nullable field '_kontoDetailListe' must contain a non-null value when exiting constructor. Consider adding the 'required' modifier or declaring the field as nullable.

Non-nullable field '_kundenCache' must contain a non-null value when exiting constructor. Consider adding the 'required' modifier or declaring the field as nullable.

Dereference of a possibly null reference.

Non-nullable property 'Konfiguration' must contain a non-null value when exiting constructor. Consider adding the 'required' modifier or declaring the property as nullable.

Non-nullable property 'Kundenstamm' must contain a non-null value when exiting constructor. Consider adding the 'required' modifier or declaring the property as nullable.

Non-nullable property 'Umsatzkonten' must contain a non-null value when exiting constructor. Consider adding the 'required' modifier or declaring the property as nullable.

Non-nullable property 'Mitarbeiter' must contain a non-null value when exiting constructor. Consider adding the 'required' modifier or declaring the property as nullable.