UEFN Editor Wont Start a Basic level

I just started a blank project in UEFN, added a height map, and a river. I can’t run the project because of this error “Found disallowed object type /Script/Engine.LevelScriptBlueprint”. I have no idea what its referencing to and have deleted some of the basic things that come with a blank project and it still won’t work. Any ideas on fixes?