AssistantFileService.CreateAsync returning "The v1 Assistants API has been deprecated."

[chocobot]

{
"error": {
"message": "The v1 Assistants API has been deprecated. See the migration guide for more information: https://platform.openai.com/docs/assistants/migration.",
"type": "invalid_request_error",
"param": null,
"code": "invalid_beta"
}
}