IWP URL - editing the page that says "Check the URL you are using to access FileMaker WebDirect"

I have an application that was using IWP under FM Server 12, to allow my friends and friends of friends to upload their golf scores, and my system would calculate their USGA handicaps.

After upgrading to FM Server 13, IWP not longer exists, and WebDirect does not support mobile devices.

So, I set up an alternative server using FM12.

A lot of guys that I don't have contact details for, used that IWP based system to upload golf scores. So I don't have a way to tell them all the new URL.

Using the old IWP URL, you are presented with a screen that says "The requested page is not found. Check the URL you are using to access FileMaker WebDirect."

I want to edit that page to add some additional information telling them the new URL etc. But I can't find any document with that content in any FM Server folder or sub folder. 

Anyone know where I can find it ?

thanks