There are a handful of issues that can come up with Online Features in SketchUp Can't connect to web tools 3D Warehouse, Extension Warehouse, Add Location and Licensing. For 2019 and later you can read this article to see how to edit the URL that is used: Troubleshooting Connectivity Issues within SketchUp | SketchUp Help The issue appears to be the URL that SketchUp uses to test whether there is an Internet connection. The problem doesn’t affect version 2019.3 and later, but could affect 2019.0, 2019.1, and 2019.2. Some extensions may be affected too, if they rely on having an Internet connection (to check the license for example). It also would prevent you from being able to add a Classic license, or use an existing Network license.

The features affected would include Add location, Generate Report, 3D Warehouse, and Extension Warehouse. Since about a month ago there has been an increase in the number of forum posts and support requests, where SketchUp is showing a message about how you need to have an Internet connection to do that feature.

Sketchup on line