Can't load persistent level after adding

I’m just learning UE4 and after following a tutorial on creating a persistent level I find I can’t load the any of the individual levels. The levels are based off raw 16 height maps from World Machine. I can use the Landscape Manager to load the height maps, so I know they are okay.

I didn’t see any bug reports on this. Does anyone have any idea what I’m missing.

Thanks.

This was never updated and I don’t remember what I did now to fix it. But I’m so many versions past this, it might not have been relevant anymore.
Just need to mark it as closed.