Ok so I fixed the issue. I was using the custom links and it just happens that there are a bunch of link for the /membres page. I just tried with /membre/... and it works!

Hi!

I was brought to modifiy a website that has been made with Joomla and whose URLs are managed by JoomSEF.

My problem is, a URL has ceased to work. I probably touched something I shouldn't have but I can't seem to find what.

This is what the url looks like atm: mywebby/membres?membre=432&
when it's original url was: myweby/membres/verdier

I don't know why this happened nor how to fix it. Nowadays, when I click on the original url, it sends me to mywebby/membres

thanks in advance for the help!