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. The features affected would include Add location, Generate Report, 3D Warehouse, and Extension Warehouse. It also would prevent you from being able to add a Classic license, or use an existing Network license. Some extensions may be affected too, if they rely on having an Internet connection (to check the license for example).
The problem doesn’t affect version 2019.3 and later, but could affect 2019.0, 2019.1, and 2019.2. It definitely affects 2018.
The issue appears to be the URL that SketchUp uses to test whether there is an Internet connection. For 2019 and later you can read this article to see how to edit the URL that is used:
Look for the part that includes
The suggested URL in that article is for cases where you have an Intranet, and can use that as a way to test for a connection. The URL used in 2019.3 and later defaults to bing.com. If you wanted to make an earlier version of 2019 match the 2019.3 version, you would change the line to be like this:
If the line doesn’t appear in the Preferences section, go ahead and add the whole line.
For SketchUp 2018 the URL is stored in a different file. On Windows the file is here:
C:\Program Files\SketchUp\SketchUp 2018\Resources\en-US\i18n.dat
The “en-US” part may need to be changed for other languages. You can edit that file with Notepad, and you will see this line:
Edit that line to change the address that is being used:
SketchUp should then be able to see that you are online.
For Mac users, use the Go menu in Finder, Go to Folder… and paste in this path:
Again, the “en-US” part may need to be changed. On Mac you can edit that file with TextEdit.
Many people reporting the problem have seen success when making this change.