Someone faced exactly the same problem before, here.
But solution hasn't been found.
You can try the following:
1. Unzip PandaWoW archive in any empty folder and just run PandaWoW.exe
In that case, the game will be downloading automatically, while you're playing. If you have bad / low internet connection you might have in-game laggs.
2. Right after you've run PandaWoW.exe at least once in option 1, you can try to replace "Data" folder in the folder with unzipped archive with your own "Data" folder, but I'm not sure it'll work, just a suggestion.
Let me know about the progress.