I have added an incorrect script text/URL into the embedded Code of a web part content editor.
<meta http-equiv="refresh" content="0;url=http://spfarm.rootname.com/sites/SITENAME/SitePages/Home.aspx">
Now, the site URL fails (The webpage cannot be found) I forgot how to get back into edit to fix ! I am only a tester not a developer, however, I do have all access rights.