400 Bad Request - Request Header Or Cookie Too Large

I have never been able to get into this forum using Chrome on a MacBook at home - except in an incognito window, I always get this error:

At work, using Chrome on Win 7 Enterprise 64 bit it has always worked nicely -- until right now. Same error message. anguished Clearing cookies has fixed it at work, I'll test at home later. Hopefully this is rare.

update: Clearing cookies worked on the MacBook too. cookie