When an instance was migrated from 5.3 to 5.4, the dashboard service checked the integrity of site home pages. If it identified any issues, the home page was not migrated. As a result, the home page for some sites, site templates, or new sites based on a site template, may be missing after the upgrade to 5.4.
Please check site templates before you create a new site. If you find a site created from a template missing a home page, please ask your system administrator to check the template before you try again. If this does not resolve the issue, please contact the HighQ support team.