For those who has General protection fault in 21:9 ratio resolutions with this game like 3440 x 1440, there is a new working solution I just noticed today in the WSGF forums.
Basically what you need to do is
1. Download the Undying Widescreen Fix made by brennan from his above attachment or from https://community.pcgamingwiki.com/files/file/422-clive-barkers-undying-widescreen-fix
and replace the UndyingShellPC.u in the Undying\System folder
2. Download dgVoodoo2 wrapper - http://dege.freeweb.hu/dgVoodoo2.html
and extract it to ...\Clive Barker's Undying\System
Copy 3 files: D3DImm.dll DDraw.dll and D3D8.dll from folder MS to the System folder
3.Run dgVoodooSetup.exe and make settings as per screenshot in WSGF forums http://www.wsgf.org/dr/clive-barkers-undying
Make sure you change the Config File Folder to your game installation System folder as shown above. Now run the Game, go in Video Options and click on the right side Change Driver - the Game restart - select Direct3D Support. One the game starts, exit the game.
4. FOV edit --> go to \system.Open user.ini. Find these lines:
And leave theme there as is for best result.
5. Resolution Edit --> go to \system. Open System.ini. Find these lines:
For 3440 x 1440p change the above values to
or other resolutions if you have any other resolution.
6. Get the D3DIM700.7z file from http://www.wsgf.org/forums/viewtopic.php?f=61&t=14163&start=10
and extract it's contents into the \system folder
7. Get Jackfuste's Undying.7z file from http://www.wsgf.org/forums/viewtopic.php?f=61&t=14163&start=10
and extract it's contents into the game's \system folder.