I go to the web site link https://software.opensuse.org/package/kdevelop4 to download and install KDevelop. I click on the "“1 Click Install”, but it fails. It brings up instead a XML-formatted page. Oddly, sometimes the “1 Click Install” works but rarely.
You need to use a web browser from the openSUSE repos (typically FF or Chromium).
The MIME type to support the on-click install won’t be found in web browsers that don’t come from the openSUSE repos.