Thank you Till for this quick reply, I want to notice that I haven' install ISPconfig v3, i have tried but I give up.
I have done many installations of ISPconfig 2 thinking I will solve the problem but i get the same result each time.
Concerning my unreachable url, in all configuration example i see, it was private address which was use, during my installation I use a Public address, i don't know if it's wrong. I'm trying to understand why my url don't work.
On my server, i host many services on my server which are used by people, format the server is not a good issue for me, i'm looking for another alternative.