configuration: is not valid domain name!

[joximu]

1st: you should give the server a name - eg. "john" or "server1" or "srv01abc" - whatever name you like (only a..z). Together with the domain name this is the Full-Qualified-Host-Name
eg. "john.domain.tld".

2nd: during ispcp setup you give this FQHN name when asked. And later you have to enter the URL you wish, the adminpanel should be available - there the default is "admin."+FQHN - admin.john.domain.tld - this you can change and enter maybe "admin.domain.tld"... (of course the DNS entry for this have to exist... also for the FQHN!)

So the FQHN is *only* used for internal (shell etc) - you never are forced to tell this name to anyone...

man hostname

cat /etc/hostname
cat /etc/hosts

/J