I've been able to download, install and run NWN from GOG. And I've been able to play the OC for a while with multiple saves with no problem.

I downloaded and installed the CEP and a module to play with it. I'm able to get the game to launch, the new module to load. I play into it for a while and then save. No problems at all. When I try to load the save, it says "Unable to load Module. It may have been corrupted or created with a different version of the toolset" (This is a paraphrase, but very close to what it says)

All my saves for the OC are fine still. And I can start a new game with the downloaded module just fine, but I can't save and reload it.

Now I've tried Shadows of Undrentide. Again, I can start it just fine, play for a while and make saves. But now my recent save game is giving me the same "Unable to load module..." message. I'm guessing the save got corrupted, as I was able to load an earlier autosave.

What's going on here? I had this game years ago, and never once ran into this issue over years of playing it, even with 3rd party downloaded modules and the CEP. Is there something wrong with the GOG version?

Any advice? Thanks in advance.