Postby aero » Sat Jul 14, 2018 4:34 am
Alright if I understand the problem here you're trying to play your level as an episode in the main game. You can create a world file and then browse for your level from there to set it up as the initial level.
To make a new world do: File > New > World map... > World Settings > Intro Level browse.
And if you don't intend to make a world map and just want to run the level check the "Hub-styled world" box on the same screen.