The same happend to me. I cant download de SDK Manager (i try on Virtual Box, Ubuntu 18, Ubuntu16, different web browsers and different internet access points). Yesterday all went smothly, but today it seems to be broken.
On my already downloaded Host, i cant update from version 1.6.1.8175 to 1.7…
Any information or alternative download point will be very appreciated.
We are experiencing an outage at the moment, and are actively working to resolve the issue. Unfortunately we don’t have an ETA for when this will be fixed. I will post here when we are up and running.