If you develop software locally on your computer and use a web server package like “XAMPP” and also have have TeamViewer installed. You might get the error message “This site is running TeamViewer” instead of the page you wanted.
The reason why you see the webpage “This site is running TeamViewer” is that TeamViewer needs to run a web server in the background and will disable Apache. To view the page you want see you must make sure that “TeamViewer” is closed, and then restart your web server. I hope this helps anyone that is banging there heads against the wall trying to figure this one out.