You have unusual errors on Civil 3D and/or you notice the command line is showing command or information in German Language.
Typical Errors may include inability to save the file once you make changes, crashing or errors with Survey Databases, inability to correctly display point styles in point groups, and other unusual errors. You may also see these tab in your Ribbon
These issues occur because these Extensions are meant for German Language Operating System and German Language Civil 3D, and are specifically designed to assist with projects in the German Speaking countries in Europe. So it alters Civil 3D and will try and pass German commands/functions to either Civil 3D or Windows OS, hence why these errors start occurring.
The solution is very simple. Close Civil 3D, then go to Control Panel, select Programs and Features (or Uninstall a Program), look for and uninstall anything DACH and/or ISYBAU.