External function core_user_external::add_user_private_files is broken

As admin, enable "Mobile services": Plugins ► Web Services ► Mobile Create a Token for the student user: Click on Site administration ► Plugins ► Web services ► Manage tokens Upload a file to get a draft item id curl -i -F filedata=@/Users/juanleyvadelgado/Documents/mypdf.pdf “ http://localhost/m/stable_master/webservice/upload.php?token=ffbe3a3002f235bf9d01fd9369e10b66&filearea=draft " Next, you can do a CURL REST call simulating a WS client with the student user. You need to replace the wstoken, draftid (with the itemid you got in the previous curl call) and the URL of your moodle instance curl 'http://localhost/m/stable_master/webservice/rest/server.php?moodlewsrestformat=json' --data ‘draftid=14&wsfunction=core_user_add_user_private_files&wstoken=ffbe3a3002f235bf9d01fd9369e10b66' | python -m "json.tool" Go to Moodle web version and check that the file was successfully uploaded to the user private files area. Now, upload a different pdf but we the same name Call the WS again but using the new draft id Check that the pdf in Moodle was updated and now you see under the same name the new document Now, upload a different document but not calling to the WS to move the files Using the draft item id you got in the previous step, upload a new different document, for doing this you must add an extra parameter to the curl call that upload files, after &filearea=draft add &itemid=draftitemid Call the WS now with the itemid, and check that both new files were added to my private files