[Bug]: OpenAI LLMs are not working in LiteLLM playground

[talhaanwarch]

Check for existing issues

• I have searched the existing issues and checked that my issue is not a duplicate.

What happened?

When I try openai LLM in plaground I got following error.

endpoint: v1/chat/completions

Error fetching response:Error: 404 litellm.BadRequestError: OpenAIException - Invalid URL (POST /v1/responses/chat/completions)No fallback model group found for original model_group=gpt-5.1-fallback. Fallbacks=[{'Generate_Chat_Default': ['Generate_Chat_Premium']}, {'Extract_Info_Default': ['llm_cache_anthropic']}, {'Extract_Info_Premium': ['llm_cache_anthropic']}]. Received Model Group=gpt-5.1-fallback
Available Model Group Fallbacks=None
Error doing the fallback: litellm.BadRequestError: OpenAIException - Invalid URL (POST /v1/responses/chat/completions)No fallback model group found for original model_group=gpt-5.1-fallback. 

endpoint: v1/responses

Error fetching response:Error: 401 litellm.BadRequestError: OpenAIException - {
"error": {
"message": "Your request to POST /v1/responses/responses must be made with a session key (that is, it can only be made from the browser). You made it with the following key type: .",
"type": "invalid_request_error",
"param": null,
"code": "missing_scope"
}
}No fallback model group found for original model_group=gpt-5.1-fallback. Fallbacks=[{'Generate_Chat_Default': ['Generate_Chat_Premium']}, {'Extract_Info_Default': ['llm_cache_anthropic']}, {'Extract_Info_Premium': ['llm_cache_anthropic']}]. Received Model Group=gpt-5.1-fallback
Available Model Group Fallbacks=None
Error doing the fallback: litellm.BadRequestError: OpenAIException - {
"error": {
"message": "Your request to POST /v1/responses/responses must be made with a session key (that is, it can only be made from the browser). You made it with the following key type: .",
"type": "invalid_request_error",
"param": null,
"code": "missing_scope"
}
}

Steps to Reproduce

1. Go to liteLLM playground,
2. Select openai llm model

Relevant log output

What part of LiteLLM is this about?

UI Dashboard

What LiteLLM version are you on ?

v1.82.3

Twitter / LinkedIn details

No response

[talhaanwarch]

Closing this because i set wrong base url.