I use the Thunderbird email program and this morning I noticed two unusual marks on my newsfeed accounts. In front of the account name was a pink triangle with an exclamation point inside of it. I right-clicked on one account listed and I noticed on the top of the menu that the Pause Updates was checked.
I don't know how it got checked, but I clicked on it to uncheck it and then I clicked on Get Messages and now everything is back to normal.