Non-nullable field 'chess' must contain a non-null value when exiting constructor. Consider declaring the field as nullable.

Non-nullable field 'auction' must contain a non-null value when exiting constructor. Consider declaring the field as nullable.

Non-nullable property 'Monopoly' must contain a non-null value when exiting constructor. Consider declaring the property as nullable.

Dereference of a possibly null reference.

Dereference of a possibly null reference.

'Map.Land.Id' hides inherited member 'Map.Block.Id'. Use the new keyword if hiding was intended.

Dereference of a possibly null reference.

Non-nullable property 'Id' must contain a non-null value when exiting constructor. Consider declaring the property as nullable.

Cannot convert null literal to non-nullable reference type.