i can't access anymore in cpanel, i get the login interface but after that i dont get the cpanel page, no problem for whm, i have try also to restart cpanel
Does the account you are logging in to have a cpanel skin assigned to it and does that cpanel skin exist on the server?
login to whm and list accounts, see what cpanel skin the domain is using and check that it exists on the server. you can change skins for a domain using modify an account.