An external applicant has informed me that they have received a registration email but that they can’t apply for a vacancy.  What should I do?

This FAQ is not relevant to job applicants

Ask the applicant if they were able to view the link in the registration email
If so, check that they clicked on the link to complete the registration process. If not, please ask them to do so.
If they are unable to see the link or url within the registration email, please ask them to try forwarding the registration email to an alternative email account, if they have one. Please note that this problem is often because their email provider disables links within emails for security purposes.
ICT have developed a potential fix for this issue but require applicants to test if it works. Please would Recruitment Administrators please notify HR by raising an iRecruitment Query in ASK HR Policy, Systems and Information should they identify any willing volunteers.