The request entity body has an incorrect value in the 'Content-Disposition' header. The expected format for this value is 'Content-Disposition:

Question

I have tried multiple HTTP APIs to post a file to OneDrive using the POST method, and I am getting always the same error.

I went to the extreme case of creating my own S

Answer 1

Try putting the Content-Disposition header as the first header after the boundary, followed by the Content-Type:

--8381f8b9-b470-43ce-b23b-f13cf5840014
Content-Disposition: form-data; name="file"; filename="hello.txt"
Content-Type: application/octet-stream; charset=UTF-8

You may need to omit the Content-Length as well to make it work. Pretty fragile really.