Upload file via client method not working

Hi, I am using the client method given in the documentation to upload file in Aras : 

[embed:dc8ab71f-3b98-42d9-b0f6-e21e02a0f8e2:afd05478-8c22-4310-88c3-b7c182d1de18:type=javascript&text=function%20processAddingFile%28file%29%20%7B%0A%20%20%20%20var%20newFile%20%3D%20aras.newItem%28%22File%22%2C%20file%29%3B%0A%20%20%20%20if%20%28newFile%29%20%7B%0A%20%20%20%20%20%20%20%20aras.itemsCache.addItem%28newFile%29%3B%0A%20%20%20%20%20%20%20%20var%20res%20%3D%20aras.saveItemEx%28newFile%29%3B%0A%20%20%20%20%20%20%20%20aras.unlockItemEx%28res%29%3B%0A%20%20%20%20%7D%0A%7D%0Aaras.vault.selectFile%28%29.then%28processAddingFile.bind%28this%29%29%3B]

 I attached this method to a button. When I click on the button and select the file I want to upload, I got this error : 

Error: Use the asynchronous file upload method/way

at Aras.Aras_applyItemWithFilesCheck [as applyItemWithFilesCheck] (include.aspx?classes…urnBlocker:28343:10)

at Aras.Aras_saveItemEx [as saveItemEx] (include.aspx?classes…urnBlocker:29949:18)

at HTMLInputElement.processAddingFile (virtualGetForm?formI…5cf&mode=add:669:10)

Do you have an idea why I am getting this error ?

Thank you!