Cant see what i build in probuilder

i am working on a parkour game and the maps are all made in probuilder there all rooms and whenever i go inside of them they dissapear

 

Sounds like backface culling. You need to make the geometry double sided, right now its only rendering from one side (as is always case unless you specify in any modelling workflow)

 

You can also use a double sided shader though will look strange with a zero unit thick doorway

 

oh ok thnx