In some cases, an organization may choose to block an Employee, Third-Party or HCP/GO User from being used in the system. Once a Employee, Third-Party, or HCP/GO is blocked the selected individual can no longer be used in requests. 

HCP's coming from Veeva or Reltio are blocked or inactivated from Veeva or Reltio. 

If the recipient on your request needs to be unblocked, please contact your organization's Master Data Administrator.