Beta version 10 produces error when streaming assistant

[Achris79]

After upgrading from bet version 8 to 10 i am facing these errors: The requested operation requires an element of type 'String', but the target element has type 'Object'.

The error is thrown while streaming the results:
CollectionResult streamingUpdates = AssistantClient.CreateRunStreaming(
Thread, Assistant, new RunCreationOptions() { AdditionalInstructions = _startMessage, });

foreach (StreamingUpdate streamingUpdate in streamingUpdates)

the sixt update causes the problem.

[Achris79]

just saw, that there are allready two open cases for this point:
203 and 200