Cannot convert null literal to non-nullable reference type.

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.

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

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

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

Cannot convert null literal to non-nullable reference type.

Cannot convert null literal to non-nullable reference type.

Possible null reference assignment.

Possible null reference assignment.