Did a quick search, and there are others round the 'Net running into that, but didn't find a fix with a quick, casual search. Most of the others are with sites like Facebook and the like. My guess is that it's likely something in network security, probably firewall blocking outbound traffic so not allowing the upload. If you've got another browser (Firefox, Chrome, etc...) installed, maybe try and see if a different browser works. When I went to 10, it also started using it's new "Edge" browser, so might try Internet Explorer as an alternate to see if that works (or vice versa, try Edge if using IE). Sorry not more help.