Site B Sandbox (Challenge Layout) Can't Open Park

[RowRow]

Wanted to build a Site B in sandbox, but when I use the Challenge mode default layout, something odd happens. I can't open the park. The 'Open Park' button on the arrival point is greyed out. I have over 300 hours in this game, so I thought I knew how to open a park at this point.

I have tested this with the challenge layout for San Diego, and had no dramas. Tested it with Isla Sorna with standard layout, and no dramas. I could open and flood my park with guests without issue. I then tested the challenge layout and Isla Sorna again and this time deleted every building to start again with more typical enclosures, but I could not open the park.

Is anyone else experiencing this? And if so, has anyone found a fix?

[Leo]

I know I don't offer any help, but I would like to point out that I have the same problem. No apparent fix so far.