### Answer
The pipeline-error-openai-llm-failed error has been reported by other users as well, and it seems to be a known issue [(1)](
) . Users have experienced similar problems, especially after making changes such as switching to a new model like GPT-4o.
From the information available, it appears that this issue might be related to Vapi's integration or a bug, which has been acknowledged and resolved in some cases.
You might want to check if the issue persists and monitor any updates or fixes from Vapi.