12.1. APP_URL is invalid
APP_URL is invalid.
.env File is not configured correctly
The .env file needs to have an APP_URL defined. The APP_URL is the url that resolves to the public folder of your helpspot installation. It should be in standard http URL format.
Secure Subdomain DNS
URL with port
DNS or Webserver Configured Incorrectly
Proper DNS configuration and web server configuration is required in addition to an accurate APP_URL setting. The APP_URL only controls how HelpSpot builds URLs. If your DNS is not pointing to the server or if you web server is not configured to receive connections and direct the browser to the public folder the APP_URL will not work properly.
Invalid or misconfigured SSL certificate
If your server has an invalid or misconfigured SSL certificate you may receive this error along with details on the nature of the issue.