'Exception.Exception(SerializationInfo, StreamingContext)' is obsolete: 'This API supports obsolete formatter-based serialization. It should not be called or extended by application code.' (https://aka.ms/dotnet-warnings/SYSLIB0051)

Dereference of a possibly null reference.

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

The annotation for nullable reference types should only be used in code within a '#nullable' annotations context.

The annotation for nullable reference types should only be used in code within a '#nullable' annotations context.

The annotation for nullable reference types should only be used in code within a '#nullable' annotations context.

Dereference of a possibly null reference.

Dereference of a possibly null reference.

Unboxing a possibly null value.