The problem
An error that sometimes happens is that posters cannot submit a given post (often a long one) and get an error something like this:
Forbidden
You don't have permission to access /newreply.php on this server.
Additionally, a 404 Not Found error was encountered while trying to use an ErrorDocument to handle the request.
Sometimes instead of /newreply.php it will be /editpost.php or something similar.
To check that this is the problem
Try making a test post containing just a few words, or just the word "test". If you can do this successfully and it appears on the board, then it is most likely something in the text of your original message that was the issue.
Why does this happen?
The board is programmed to recognise and disallow some expressions that might be used by hackers to attack the board. Unfortunately now and then this function bars completely innocent text.
Is there an exact list of what expressions are barred?
No. There is a (very long) list of words that are usable in SQL but that really doesn't narrow the field very much - nor does every use of any word in that list trigger the problem.
Usually it is some particular combination of two or more words, rather than a single word, that triggers the problem.
So how to get around it?
Unfortunately the only way we have found around this bug is trial and error.
Go through your post sentence by sentence, and in turn, try cutting out a sentence (use Edit:Cut) and submitting in preview mode.
If your post still doesn't go through, that sentence is probably not to blame. Paste it back in and try cutting the next.
If your post does go through, you have identified the sentence that the board takes exception to. You can now try cutting out groups of a few words in the same manner, or just radically reword the entire sentence.
If your post is very long you can use the same trial and error process paragraph by paragraph, then sentence by sentence within the troublesome paragraph.
If, no matter which sentence you cut out, you still have problems, you may have to try radically rewording the entire post.
http://www.chesschat.org/showthread...-or-can-t-edit-post-quot-Forbidden-quot-error