Why can't I connect to Ubuntu One?
Solution 1:
The Ubuntu One cloud services have been discontinued. Here's the announcement from Canonical just about one year ago.
Today we are announcing plans to shut down the Ubuntu One file services. This is a tough decision, particularly when our users rely so heavily on the functionality that Ubuntu One provides. However, like any company, we want to focus our efforts on our most important strategic initiatives and ensure we are not spread too thin.