You should try re-install fresh, 1st game, 2nd bugfix, 3rd pc mod, also if you have previous saves, try loading in a previous state, some places like some parts of the house or in the school could cause more problems. You can try also to reload your saves in a previous version of the game (0.89 works pretty good). If all of the above fails, try to remember the zone or the mission that bugged your save file, maybe in that way we can help in a more effective way.
EDIT: also remember that you need to copy the config.rpgsave with the global.rpgsave if you want that the files load at all.