Send files to another domain doesn't work

Hello everyone,
I have my form on “” domain and i have my endpoint set to “”.
However my second server fails to read the file since it says that the Content-type isn’t multipart/form-data.If i set my endpoint to “/upload” and handle the files on the same server,it works however.
Is that normal behaviour?
I am running a Go server for both of those servers.

Here is a snippet of the .html

              <script src=""></script>
                var uppy = Uppy.Core()
                  .use(Uppy.Dashboard, {
                    inline: true,
                    target: '#drag-drop-area'
                  .use(Uppy.XHRUpload, {
                  endpoint: '',

                uppy.on('complete', (result) => {
                  console.log('Upload complete! We’ve uploaded these files:', result.successful)

and here is a snippet of the Go server

func uploadFileHandler(w http.ResponseWriter, r *http.Request) {
    file,_,err := r.FormFile("uploadFile")
    defer file.Close()
    fileBytes, err := ioutil.ReadAll(file)
    newFile,_ := os.Create(newPath)
    defer newFile.Close()
    _,err := newFile.Write(fileBytes)
func enableCors(w *http.ResponseWriter) {
    (*w).Header().Set("Access-Control-Allow-Origin", "*")
    (*w).Header().Set("Access-Control-Allow-Methods", "POST, OPTIONS, GET")

and here’s a picture of the error

Fixed it!Was a cors problem of course :slight_smile: Had to enable preflight check for the OPTION method.

if r.Method == "OPTIONS"  {

Put this at the start of your method,if you are having the same problem.