Don’t worry, All Nations created through Nationbuilder are inaccessible for short time. Actually, it is a server issue on which team is working on. please keep patience, the site will be up in short time. Nationbuilder engineers are working on it to fix the problem as soon as possible. it will accessible automatic once engineers solve the problem from their side, we do not need to do anything from our side to make it up.
You can get a status update from here.
http://status.nationbuilder.com/
Please read more at https://www.corewaysolution.com/technical-expertise/nation-builder.html to know our skill and expertise as certified Nationbuilder agency.