Cannot convert null literal to non-nullable reference type.

Possible null reference argument for parameter 'parentId' in 'Activity Activity.SetParentId(string parentId)'.

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

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

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

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

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

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

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

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

Cannot convert null literal to non-nullable reference type.

Dereference of a possibly null reference.

Dereference of a possibly null reference.

Possible null reference assignment.

Dereference of a possibly null reference.

'JsonNetSerializer.Customize(Action<JsonSerializer>)' is obsolete: 'Use Configure(Action<JsonSerializerSettings> configure) instead. This overload will be removed in the next major release.'

Dereference of a possibly null reference.

Dereference of a possibly null reference.

This async method lacks 'await' operators and will run synchronously. Consider using the 'await' operator to await non-blocking API calls, or 'await Task.Run(...)' to do CPU-bound work on a background thread.