several wikis stopped working spontaneously
My initial guesses would be to check your .htaccess settings and possibly try enabling $wgUseTidy. Are you using profiling or have a StartProfiler.php file in your root folders?
htaccess settings seem to be fine, but then everything's working at the moment. I'll check next time it happens, and I'll look into the UseTidy (this latest problem did occur at the same time as some html using spambots, but the sites came back on their own with the same html still there). Unless profiling is something I might have done accidentally, I am not using it. Thanks! Modrobene 05:27, 12 December 2011 (UTC)
The second error (unexpected $end, yadda yadda) sounds like when you added that line to LocalSettings.php, you forgot a semi-colon (or removed the closing */ of a comment, or some other syntax error was made).
The first error (Mediawiki Internal Error) is really hard to debug without the $wgShowExceptionDetails = true; However, it is unlikely to be caused by lack of html tidy (Which fixes html errors) or stuff wrong in a .htaccess file (which gives a different type of error message - typically an apache generated 500)
