after installing phpBB SEO Ultimate SEO URL mod
when creating a new topic i get this:
Internal Server Error
The server encountered an internal error or misconfiguration and was unable to complete your request.
Please contact the server administrator, and inform them of the time the error occurred, and anything you might have done that may have caused the error.
More information about this error may be available in the server error log.
The URL in that moment is:http://www.rosupak.org/posting.php?mode=post&f=10
P.S. IT DOES CREATE A TOPIC DESPITE OF ERROR