Since the file path is valid, the issue is likely how the file is being sent. Using a raw stream can omit filename and MIME type in the multipart payload, which often causes silent 500 HTML errors on upload endpoints. Ensuring the request includes explicit file metadata (name and audio MIME type) should resolve it or at least surface a proper structured error. I can help adjust the request formatting so the server correctly interprets the audio file and we can see a proper structured error if anything else is wrong. @DeadNecromancer