Error raised when uploading to local but not raised on production blobstore

[cybercent]

Hi,

I'm sending 2 files to my local GAE blobstore from an iPhone app.
The files are uploaded and visible in the Blobstore Viewer, but a mime: invalid media parameter error is raised.

In production the files are also uploaded and no error is raised.

blobs, url_values, err := blobstore.ParseUpload(r)
if err != nil {
 // err is "mime: invalid media parameter"
}

For reference, the swift code that I use to set the mime types.

multipartFormData.append(videoData as Data,
withName: "file[]",
fileName: "\(videoName).mp4",
mimeType: "video/mp4")

multipartFormData.append(audioData as Data,
withName: "file[]",
fileName: "\(audioName).caf",
mimeType: "application/octet-stream")

I've tried with different mime types, and also only sending 1 file instead of 2. Same error on local, no error on GAE production.