ดูต้นฉบับสำหรับ มีเดียวิกิ:Apierror-cannot-async-upload-file

The parameters <var>async</var> and <var>file</var> cannot be combined. If you want asynchronous processing of your uploaded file, first upload it to stash (using the <var>stash</var> parameter) and then publish the stashed file asynchronously (using <var>filekey</var> and <var>async</var>).