To check for being online to access the SketchUp License Server/ 3DWarehouse/ Extension Warehouse/ Add Location/ Help System don’t use the recent default
i18n.dat [ONLINE CHECK] ONLINE_TEST_URL=http://www.google.com/ncr
which can be blocked resp. redirected by the users firewall resp. proxy.
Use your own domain “sketchup.com” as e.g. “help.sketchup.com” instead which is finally required for accessing the ressources mentioned above anyhow.
• SketchUp Help Center : Can’t connect to web tools; 3D Warehouse, Extension Warehouse, Add Location and Licensing
(for complete info select version SU 2016 sigh)