Please do a full **clean** re-install:
- move any valued save games elsewhere
- "uninstall" in Steam-EU4
- manually delete both the Steam/SteamApps/common/EU4 AND Documents/Paradox Interactive/EU4 folders
- re-install game in Steam, run a Steam Verify when done.
- start the game with no mods active and test
In particular make sure there are no files or folders left under either the Steam EU4 or Documents EU4 locations, before installing again.
**File Locations on Mac OS X**
The executable and DLC folder are in Users/USER/Library/Application Support/Steam/SteamApps/common/Europa Universalis IV/
To see it go to the Finder, hit command-shift-G (ie Go To) and type in ~/Library/ .
The user files (settings.txt, error logs, saved games, gfx, mods) are in /Users/USER/Documents/Paradox Interactive/Europa Universalis IV/ .
IF that doesn't help:
Please attach here your Documents/Parad...