Bug: iOS - Content is null - 400 error

[jerry2007]

Describe the bug
When I call one of method InvokePromptAsync/GetChatMessageContentsAsync/GetStreamingChatMessageContentsAsync on iOS. The error is raised.

Microsoft.SemanticKernel.HttpOperationException
Invalid value for 'content': expected a string, got null.
Status: 400 (model_error)

Content:
{
"error": {
"message": "Invalid value for 'content': expected a string, got null.",
"type": "invalid_request_error",
"param": "messages.[0].content",
"code": null
}
}

Headers:
x-ms-region: REDACTED
apim-request-id: REDACTED
x-ratelimit-remaining-requests: REDACTED
x-ms-rai-invoked: REDACTED
X-Request-ID: REDACTED
ms-azureml-model-error-reason: REDACTED
ms-azureml-model-error-statuscode: REDACTED
Strict-Transport-Security: REDACTED
azureml-model-session: REDACTED
X-Content-Type-Options: REDACTED
x-envoy-upstream-service-time: REDACTED
x-ms-client-request-id: 7f2d2543-dde4-45fc-87c3-934a33753cee
x-ratelimit-remaining-tokens: REDACTED
Date: Fri, 12 Jul 2024 07:42:46 GMT
Content-Length: 187
Content-Type: application/json

To Reproduce
Steps to reproduce the behavior:

1. In Maui iOS call InvokePromptAsync/GetChatMessageContentsAsync/GetStreamingChatMessageContentsAsync
2. See error

Expected behavior
Can call these methods with no error

Platform

• OS: iOS
• IDE: Visual Studio
• Language: C#
• Source: NuGet package version 1.15.1

[alliscode]

Hi @jerry2007 and thanks for filing this issue. Would you be able to share a snippet of the code that replicates this issue for us?

[jerry2007]

` _history.AddUserMessage(question);
OpenAIPromptExecutionSettings openAIPromptExecutionSettings = new()
{
ToolCallBehavior = ToolCallBehavior.AutoInvokeKernelFunctions,
Temperature = 0.2
};

var answer = "";
await foreach (var result in _chatCompletionService.GetStreamingChatMessageContentsAsync(
_history,
executionSettings: openAIPromptExecutionSettings,
kernel: _kernel,
CancellationToken.None))
{
answer += result?.Content;
yield return result?.Content;
}`

this code crash on line with foreach....

[jerry2007]

this is related:
#6993

[jerry2007]

I found out that downgrade nuget Azure.AI.OpneAI to version 1.0.0-beta.15 in semnatic kernel project Connectors.OpenAI works correctly.

Azure/azure-sdk-for-net#44174

[arafattehsin]

Unfortunately, this issue not resolved in the latest versions. We use Structured Outputs which is not supported in earlier versions. :(