I made a fix for the Doppelganger crash a while back but never published it because I was never able to verify it worked. For some reason I couldn't get it to crash with or without the fix. I still can't reproduce the crash, but I uploaded the updated game data here anyway in case someone wants to try it.
To use it, open Steam, right click on DEVIL DUMPER DORIS in your library, go to Properties, then Installed Files and click Browse. That should open the folder with the game files. First, rename the data.win that's already there to something else (like data_original.win) so you have a clean copy if you want to go back. Then copy my updated version of data.win to that folder and you should be good to go.
If anyone decides to use it, let me know if you run into the crash while using it.