A community member is trying to set the LLM (Large Language Model) to "gpt-4o" but is encountering an error stating that the model name is unknown. The community member has updated the llama-index-llms-openai package but is still facing the issue. Another community member suggests trying to reinstall the package, but the original poster still encounters the error and wonders if they need to relaunch their Jupyter Notebook for the changes to take effect. There is no explicitly marked answer in the comments.