This will allow you to load old save games even after mods get updated

Step 1:

Subscribe to the save game editor
https://steamhost.cn/steamcommunity_com/sharedfiles/filedetails/?id=2892778705

Step 2:

Open save game editor at:
Steam\steamapps\workshop\content\400750\2892778705

Step 3:

Make a backup of your save then load your save at:
Documents\My Games\gates of hell\profiles\xxx\campaign

xxx is your unique profile number

Step 4:

Remove all activated mods from the save. Then click save