Your message means that the address www.facebook.com is blocked or redirected to some empty content. If so, the browser you use have absolutely no impact.
Check your hosts file: \WINDOWS\system32\drivers\etc\hosts. It's an extentionless text file. Open it in notepad.
Do you find an entry with "127.0.0.1 www.facebook.com"? (without quotes) This redirect facebook to the local loopback, or your own computer. Remove that entry and save the file.
Do you connect through a router? Check that the router is not set to block facebook.
For the last 3 days, did you try to access facebook through someone else LAN? That someone have probably blocked access to facebook. Extremely easy, I've done exactly that on my home network in a few seconds.
Electro
January 2012