We are currently experiencing a flood of requests from bots scraping the forums. Unfortunately it has gotten to the point where it is negatively impacting the site. As a result the forums may be slow and you may periodically experiance an error message.
We are aware of the problem and apologize for the inconvenience.
It is most likely a forum glitch, so it's advisable if you wait it out and try to edit your signature again after a few minutes or so. Or you could try to log out and back in, but it's probably a glitch and you can probably edit your sig again after a while.
...The last time someone posted here was November 20th. The seven line rule is automated, I believe, and may depend on your current user rank or something.