There is no link on a Plesk Client subscription in CP.
Top > Service Director > Plesk Manager > Clients when the Client name is clicked on the following error emerges
Error-TEXT: 59:25] [FATAL]  [Error::throw] URI handler (HSPC::Plesk::PleskClientList->teaser_office) error: subscription id is undefined. Error-LOCATION: /usr/lib/perl5/site_perl/5.8.8/HSPC/Logger.pm:160
The Client was migrated between Plesk nodes by Plesk means and still lies in Conflicts Resolver.
Top > Migration Director > Conflicts Resolver > Plesk Clients, locate the Client in question and resolve its conflict as described in the Provider's Guide.