As I was trying to redirect some old pages on my other site (morkalork.com) I added the following line in my .htaccess file:
RedirectMatch ^/mork/article/([^/]+)/ /index.php?page=article&id=$1 #LEGACY REDIRECT
I then got the ol’ 500 Internal Server Error and the error log contained this error:
[Sun Aug 12 12:29:48 2012] [alert] [client 127.0.0.1] C:/wamp/www/morkalork/.htaccess: RedirectMatch takes two or three arguments, an optional status, then a regular expression and destination URL
It turned out in my cause to be due to the comment at the end (possibly the tabs as well). I removed everything after “…&id=$1” and tried again and voila(!), it worked! I’ve also read about people having this error whenever they’ve accidentally added a space somewhere which breaks the syntax.