It seems this was not related to the X3 update. When I try to load a resized image on your website, it seems to just reload the entire index home page:
https://www.photographe-mariage.net/render/w640-c2.1/2.Categories/1.moments-preliminaires/20110601_125520_D7C_5552.jpg
As far as I can see, this is not only resized images. It's loaded the root page for ALL your pages. For example:
https://www.photographe-mariage.net
/Categories/moments-preliminaires/
In fact, it doesn't matter what you write in the url for your website. It always displays the index home page:
https://www.photographe-mariage.net
/doesnt/matter/what/url/
This means rewrite rules for resized images is not working, and I don't think it was working before you updated either. I checked your diagnostics page:
https://www.photographe-mariage.net/?diagnostics
You are aware you are using NGINX server? Nginx does not support .htaccess files. Have you (or someone) setup config for nginx? I have a nginx config example setup here:
https://gist.github.com/mjau-mjau/6dc19 ... e566a8457b
However, you should not really be using NGINX unless you have the expertise the configure it properly. Nginx servers don't support .htaccess files (like Apache), which contain critical rules for rewrite requests for pages and resized images. Also, since you are using NGINX, my guess is that your server is setup so that if "file not found", it will just display the index home page ... This is basically what I'm seeing.
If you are using pro hosting, you should really be using Apache option. Your website was working earlier, so someone has just updated your hosting to nginx without asking or taking any precautions? Anyway, you need NGINX-specific config, and you must make sure your NGINX server does not intercept "files not found" and just rewrite to root index.