In Sketchup 2015 Pro, I’m having this problem now as well. I’ve noticed it’s been getting slower and slower for the past month, and today it has completely stopped responding.
I cleared all cookies, both for Sketchup and IE, and it’s still not loading anything. I can’t upload my models into the 3d warehouse nor can I view/download models.
The 3d warehouse works if I go there manually through firefox/chrome, but dang is it slow.
Still suffering same problem in 2015 Pro. Seems to open warehouse first time then stalls every other time. Can sometimes make it work by closing SK and reopening. Warehouse works from browser (IE 11) but if I download from this it tries to open in SK 8.
This is a fundamental feature of Sketchup and if it don’t work, it’s busted!