Hi,
I use a WEB component to open a CSV file on en server.
I want to modify it and save it.
I succed in opening it.
But I don't know how to save it.
you are downloading that file!
is this your own server?
How to use the PostFile block in App Inventor
the easier solution is to use a ftp extension, for example App Inventor Extensions: FTP | Pura Vida Apps
there are also other ftp extensions...
Taifun
Trying to push the limits! Snippets, Tutorials and Extensions from Pura Vida Apps by 
Taifun.
maybe only downloading the content of the file ?
The file download with the web component seems to be broken at the moment....
Yes I download it.
Yes it is.
you are correct... my french is a bit rusty... 
then you can follow my previous suggestions
Taifun