I had the same problem (judging by the "symptom"): stuck at 100%
How did I "fix" it?
- bypass the launcher: can the game run without the launcher? yes. (if not, completely delete the game and reinstall it)
- remove all the saves: can the launcher work? yes. (if not, delete Steam/GOG and reinstall everything and this game)
- start a new game using the launcher. make a new save and reload it to verify everything works.
- move 1 old save back to where it was. restart the game to load the old save to verify everything works.
- move all old saves back. restart the game to load old saves to verify everything works.
I essentially made the game fix itself, and it did (meaning: most likely this was an issue related to caching and/or something like inconsistences in registry settings etc.).
Hope it helps. Good luck.
