Thanks for your answer (I didn’t get the return of my server about my version of linux).
I downloaded the file but there wasn’t two choices, only a single file to download: PNGOUT-2015319 … tar.gz.
I put in the dossier ewww (permissions 755) with the BIN mode.
I updated the backoffice, clicked on “automatically”, but nothing happens.
Did I miss a step?
The error message:
Pngout was not installed: extraction of files failed. Make sure this folder is writable: /homepages/0/d464806594/htdocs/isabelleharpey.com/wp-content/ewww/
And
Total Savings: 29.64 kB
If updated versions are available below, you may need to enable write permission on the /homepages/0/d464806594/htdocs/isabelleharpey.com/wp-content/ewww/ folder to use the automatic installs.
*Updates are optional, but may contain increased optimization or security patches