Complete details are available in the blog at:
A summary from the blog:
"What I explained to the students was this: admin console must be trying to check for updates while
loading. If it cant connect to the update server (a fast kind of failure) it ignores the error and finishes
loading. No problem there, only a few seconds lost. But when it can connect to the update server and
the server is just not responding (a slow kind of failure) then it will wait forever for a reply and hence
not finish loading"