I tried logging into Gmail this morning at home and got the error below. I figured maybe something was screwy on my home laptop, but when I tried to access Gmail from my work computer, I get the same error.
Make sure your cookies are enabled. To enable cookies, follow these browser-specific instructions.
If you have cookies enabled but are still having trouble, clear your browser’s cache and cookies.
If clearing your cache and cookies doesn’t resolve the problem, try adjusting your browser’s privacy settings. If your settings are on high, manually add www.google.com to your list of allowed sites. Learn more