I try to update a (little) file and want to supress the yellow dialog.
The silence mode seems not to be right, cus the user have to choose the file before.
the dialog is not suppressable.
But: there is a special control for "file interfaces" maybe this is exactly the right one for you: CLIENTFILETRANSFER, please check demo workplace "General > Client Intergation > Automated File Transfer" and below also "Client File API > File Poller".
Please note: the file intreface components are suitable for small file sizes (<1 MB) only. There data is embedded into the normal requiest/response of CaptainCasa/JSF.