microsoft/autogen · error · InvalidOperationException

Invalid message type: {m.GetType().Name}

Error message

Invalid message type: {m.GetType().Name}

What it means

Error "Invalid message type: {m.GetType().Name}" thrown in microsoft/autogen.

Source

Thrown at dotnet/src/AutoGen.AzureAIInference/Middleware/AzureAIInferenceChatRequestMessageConnector.cs:182

    {
        return messages.SelectMany<IMessage, IMessage>(m =>
        {
            if (m is IMessage<ChatRequestMessage> crm)
            {
                return [crm];
            }
            else
            {
                var chatRequestMessages = m switch
                {
                    TextMessage textMessage => ProcessTextMessage(agent, textMessage),
                    ImageMessage imageMessage when (imageMessage.From is null || imageMessage.From != agent.Name) => ProcessImageMessage(agent, imageMessage),
                    MultiModalMessage multiModalMessage when (multiModalMessage.From is null || multiModalMessage.From != agent.Name) => ProcessMultiModalMessage(agent, multiModalMessage),
                    ToolCallMessage toolCallMessage when (toolCallMessage.From is null || toolCallMessage.From == agent.Name) => ProcessToolCallMessage(agent, toolCallMessage),
                    ToolCallResultMessage toolCallResultMessage => ProcessToolCallResultMessage(toolCallResultMessage),
                    AggregateMessage<ToolCallMessage, ToolCallResultMessage> aggregateMessage => ProcessFunctionCallMiddlewareMessage(agent, aggregateMessage),
                    _ when strictMode is false => [],
                    _ => throw new InvalidOperationException($"Invalid message type: {m.GetType().Name}"),
                };

                if (chatRequestMessages.Any())
                {
                    return chatRequestMessages.Select(cm => MessageEnvelope.Create(cm, m.From));
                }
                else
                {
                    return [m];
                }
            }
        });
    }

    private IEnumerable<ChatRequestMessage> ProcessTextMessage(IAgent agent, TextMessage message)
    {
        if (message.Role == Role.System)
        {

View on GitHub (pinned to 027ecf0a37)

Solutions

1. Use only supported message types for this connector

Example fix

Convert to TextMessage/ImageMessage/ToolCallMessage before sending

When it happens

Trigger: Thrown at dotnet/src/AutoGen.AzureAIInference/Middleware/AzureAIInferenceChatRequestMessageConnector.cs:182 when the library encounters an invalid state.

Common situations: See trigger scenarios.

AI-assisted analysis of microsoft/autogen@027ecf0a37 (2026-08-15). Data as JSON: /api/errors/2c23a61aa98c637c. Report an issue: GitHub.