I just rebuilt one of our websites using silverstripe. amazing product.

I have forum which is stored in a folder in the site root.

i create a redirector page within SS with a url to the folder (http://www.mysite.com/folder)

i have tried using the folder name without the domain, etc... as the url and same result.

it will only work if i add index.php to the url. but this is not ideal as we have alot of people who have the site bookmarked.

I get the SS error page with the following message:

Website Error
Not Found
The website server has not been able to respond to your request.

how do i get this to work?

I don´t know why you used a redirect page. Maybe you can use the method "redirect" from the class "Director".

If its just a link to static target, why don;t you code the URL in the template.

But if you're using other Forum software that resides in that folder it should work without the index.php unless it has its own htaccess URL rewrites, then I can see it causing problems. The SS install may have overwritten its rules.