Possible null reference assignment.

Converting null literal or possible null value to non-nullable type.

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

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

Cannot convert null literal to non-nullable reference type.

Cannot convert null literal to non-nullable reference type.

Cannot convert null literal to non-nullable reference type.

Cannot convert null literal to non-nullable reference type.

Nullability of type of parameter 's' doesn't match overridden member (possibly because of nullability attributes).