I am trying to install the ADT plugin for Eclipse. However, after I have went to \"Install New Software...\" and entered the plugin location https://dl-ssl.google.com/android/ec
I had the same problem and it was driving me nuts. I kept trying for a couple of hours--getting the same error message--and at once it worked! So if I were you I'd just leave it for a bit and come back in a couple of hours and try again. There are several other suggested solutions online that I found, but neither of those seemed to make a difference.