word builder

I created a custom map with the in-game Civ 6 (Epic) worldbuilder map editor starting with an empty map, painting the lands, oceans, contenants, land features, and adding resources and natural wonders. Then I changed the four required textboxes in the map details so that the map doesn't show...

So I've enabled map builder... created and saved a test map... but cannot play it... I've downloaded various map mods... examined file/directory structure... tried to mimic.... but no dice. All I want to do is create slightly modified random maps -- adding stone here, moving around natural...