Apache Friends Support Forum

I am running Fedora 26. XAMPP installed ok, but when I try to follow the directions for installation of the control panel I get an error cannot read ":0"
Has anyone had this problem? How do I solve it?

This is an addition. I get to the welcome page for xampp at 127.0.0.1, but the test.html file in /var/www/html cannot be reached. These problems might be connected, wish I could see the ports in the control panel.