Obsidian Whisper: "Error parsing audio: Request failed with status code 400"

Hi,

I started using the Whisper plugin a few days ago. I am amazed how well it transcribes my speech into text and embeds it directly into a markdown link.

Unfortunately I get this error, when I want to upload an already recorded file (in m4a-format and size of 1MB). I still have 10$ left in my OpenAI credit balance, so lack of credit cannot be the reason.

Do you have an idea, what the problem could be?

Thanks in advance
kind regards,

Silias

update:
when I converted the file from m4a to webm the transcription worked - now error was thrown…