This file will let you run Portal Pro after updating to the SteamPipe version of Portal. If you have not updated Portal, you do not need this patch. Thanks to THEJackinator/Technogeek1994 for providing the file. Installation instructions are below.
Installation Instructions
Find the GameInfo.txt file in the mod directory (e.g., C:\Steam\steamapps\sourcemods\portal pro\GameInfo.txt).
Its just a .txt file, why?
This is just a patch for version 1.1. To get the latest verison go here. Moddb.com