Try this:
Validate your files in Steam and make sure there is no mods folder at all. No POIs, GUI mods, etc.
Use A18p4b4RWG01 as your Game Name AND World Generation Seed in a single player game. It should give you East Roboda County as the Generated World Name.
Once it has generated and you are in game, exit the game to the main menu and go to the world editor.
Let us know your results. If it fails to load again, please submit that output log.