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).

This issue primarily affects users running SketchUp 2018 and older.

Google have recently disabled the website that SketchUp uses to check if there is an internet connect. Because the web page doesn’t exist SketchUp can’t access it and thinks there is no internet acces.

For 2019 and later you can read this article to see how to edit the URL that is used:

https://help.sketchup.com/en/sketchup/cant-connect-web-tools-3d-warehouse-extension-warehouse-add-location-and-licensing 72

Look for the part that includes "OnlineTetURL": "",

 

If the line doesn’t appear in the Preferences section, go ahead and add the whole line.

"OnlineTestURL": "https://www.bing.com/",

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

Right click the i18n.dat file and choose open with with Notepad, and you will see this line:

ONLINE_TEST_URL=http://www.google.com/ncr

Edit that line to change the address that is being used:

ONLINE_TEST_URL=https://www.bing.com/

save the chanages

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:

/Applications/SketchUp 2018/SketchUp.app/Contents/Resources/Content/Resources/en-US/i18n.dat

Many people reporting the problem have seen success when making this change.