This happens regardless of whether you are logged in or not. IIRC it's some weird implementation bug with how they use webworkers. There was an HN thread on it a couple of months ago that prescribed some fixes. It varies by browser, browser version and some other things like what chrome may be a/b testing for you. The fixes are temporary, though.

Dunno why Twitter seems to have completely deprioritized the issue though. They change the error message every once in a while but nothing else.