Mintplex-Labs/anything-llm · error · Error

Stream returned undefined chunk. Aborting reply - check…

Error message

Stream returned undefined chunk. Aborting reply - check model provider logs.

What it means

Stream guard in OllamaAILLM.handleStream: an iteration of the streaming response yielded an undefined chunk, indicating the model provider dropped or corrupted stream data; the stream is aborted early, preserving any text already generated rather than emitting garbage.

Solutions

1. Check the model provider logs for stream errors.
2. Retry the request.
3. Verify the model supports streaming.

When it happens

Trigger: Thrown when a streamed chunk is undefined.

Common situations: Provider stream interrupted or malformed chunk.

AI-assisted analysis of Mintplex-Labs/anything-llm@3aec848f28 (2026-08-18). Data as JSON: /api/errors/aa441e38ee63b7d5. Report an issue: GitHub.

Appendix: source

Thrown at server/utils/AiProviders/ollama/index.js:376

      let usage = {
        prompt_tokens: 0,
        completion_tokens: 0,
      };

      // Establish listener to early-abort a streaming response
      // in case things go sideways or the user does not like the response.
      // We preserve the generated text but continue as if chat was completed
      // to preserve previously generated content.
      const handleAbort = () => {
        stream?.endMeasurement(usage);
        clientAbortedHandler(resolve, fullText);
      };
      response.on("close", handleAbort);

      try {
        for await (const chunk of stream) {
          if (chunk === undefined)
            throw new Error(
              "Stream returned undefined chunk. Aborting reply - check model provider logs."
            );

          if (chunk.done) {
            usage.prompt_tokens = chunk.prompt_eval_count;
            usage.completion_tokens = chunk.eval_count;
            usage.duration = chunk.eval_duration / 1e9;
            writeResponseChunk(response, {
              uuid,
              sources,
              type: "textResponseChunk",
              textResponse: "",
              close: true,
              error: false,
            });
            response.removeListener("close", handleAbort);
            stream?.endMeasurement(usage);
            resolve(fullText);

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