For MacOS users
My system: Mac Mini M1
If you change graphic settings (Ambient Occlusion in my case) and your game close and don't launching anymore and reinstalling game and Plarium play launcher does not help you, than try to do this:
1. Go to the path /Users/YOUR_USER_NAME/Library/Preferences
2. Delete file "com.plarium.raidlegends.plist"
3. Go to the path /Users/YOUR_USER_NAME/Library/Saved Application State
4. Delete folders: "plariumplay.savedState" and "com.plarium.raidlegends.savedState"
This steps helped me.