We’re aware that at this time there are a lot of frustratingly weird errors all over the documentation on the Mozilla Documentation Center wiki. I’m actively working on getting these resolved. There is an underlying technical problem — apparently a database connection issue — causing these errors to appear.
Some folks have been trying to help by editing the effective articles to work around the error by not using the extensions that, for example, provide syntax highlighting. This is not actually helpful and is in fact counter-productive, as it makes testing and attempting to fix the problem harder. Please leave these alone so I can concentrate on getting things fixed properly. I am coordinating getting this repaired and hopefully it will be all back to normal soon.
Thanks for your cooperation and enthusiasm!