1. Check if you have restarted /started the Application Server where you have installed site24x7_apminsight gem.
2. If you have restarted/started the Application Server and still the monitor is not added, check if you are able to connect to the Site24x7 server (https://site24x7.com) from your browser.
3. If there is a proxy server between APM Insight gem and Site24x7 server, specify the Proxy server configuration.
To check if there is a proxy, open a browser in the APM Insight gem installed machine and try connect to https://site24x7.com. It should display the login page of Site24x7. Check whether any proxy server is configured in the browser and specify those values in apminsight.conf