Hello there !
I tried this and it worked :
Disable " Internet Explorer " Offline mode.
Even if that's not your default browser, some anti-virus activate this option, don't know why. But I've unchecked and I could connect myself.
I hope it will help.
So you have to click on "File" then "Offline Mode" in the upper right corner. If you don't see the menu bar, try hitting F10.