I started up Titanium Studio with Node.JS installed. On startup, it began installing 'titanium' CLI automatically in a Terminal view (off to the right, rather than along to bottom right like a console). While it was running, the Titanium SDK Update toast popped up. I clicked it. It hangs the IDE for around a minute. It looks like it's frozen for good, but I think it may continue once the installs are done in the Terminal (though that stops updating too).