Can you reach https://3dwarehouse.sketchup.com/ from a browser? From Chrome? Or just in-client SketchUp. Does Extension Warehouse or other internet things from SketchUp, e.g. geo-location work?
OK, so similar kind of troubleshooting: can you get to http://extensions.sketchup.com/ in a browser? And in-client, can you get to 3dwarehouse and geo-location? i.e.- can SketchUp get to the internet at all?
I turned off my firewall and still the same… If I use the web I can get access but it’s very slow. A friend of mine has the same issue. (different network of course)