Something didn't work

When trying to access the Service Catalog, I get a message that says “something didn't work”. I have downloaded and am using Copenhagen “Theme version 4.3.0-beta.4”.  Have tried on multiple different browsers, and incognito mode.  When I click on the Service Catalog icon, it looks like it about to load correctly for a second, before saying “Something didn't work. Unable to load. Give it a moment and try again.”