error/admin/installhijacked
From MoodleDocs
This error compares $adminuser->lastip with the users current IP address.
It will occur if a site has been installed on a server via the cli scripts in admin/cli (install_database.php or install.php). After installing the site remotely, visiting the site via a web browser (a different IP) will trigger the error message.
Workaround:
Update the database directly with your current IP address (table: mdl_user, field: lastip, SQL: UPDATE mdl_user set lastip='159.245.48.2' where username='admin';).
