Have you tried to clear Chromes's cache? https://support.google.com/accounts/answer/32050?hl=en
Another approach is to use the browser in incognito mode.
Chrome's incognito mode uses a fresh cache and cookies and gets rid of it off when you close the incognito window.
And you shouldn't worry about that NO APIS KEY error, it's minor. You can do the pset normally even with that warning (I had it when I completed this pset and I still have it to this day)