How to correct installation

the only way I have to change one parameter in my installation is to reinstall all from scratch.

Is it a way to change yunohost ?

So we can help you, can you be more specific about what parameter you want to change?

I wanted to change the default domain of yunohost. Yesterday I tryed with the root domaine and all works fine. Today I try with a sub domaine and I cannot do anything. No letsencrypt

Please be more specific than “I cannot do anything. No letsencrypt” …

If you want to change the main domain, you can do so via the admin interface (in the page related to the domain) or with yunohost tools maindomain -n