Hello, i am having the same problem here. When i click the sketchucation plugin i get that pop up window which tries to load for a few seconds and then i get the message :"Navigation to the webpage was canceled"
I Also cannot download 3d Warehouse components but i can browse through them. The extension warehous also doesnt work, it tells me it requires an internet connection.. I downloaded and installed the latest IE 11, added the link to the trusted zone, allowed sketchup through firewall but same problem..
W