Firefox embarrassing problem!

This problem happened to me when I wanted to wake up my pc and leave it in suspension and of course had left a couple of pages open in my Firefox browser.

When you press Enter, I came this message:

Well, this is embarrassing.

Firefox had a problem in recovering the windows and tabs.
It can be caused by a recently opened website.

Try:

- Delete one or more tabs you believe could be causing the problem.
- Start a new browsing session.

I decided to do was to re-open a new browsing session, ie, close all tabs and I opened my Firefox browser.