Can't build up against mountain side

The template shows that it can be built there, but the builders only build the front three walls and then leave it with scaffolding and all still there. they must be on strike or something

try building slowly piece by piece… example build the floor 1st then build the walls
to do this 1st build the floor tell them to build and close the custom building then open custom building again and add walls i’ve used this method to build docks over water and avoid the build idle bug

let me know how it goes !

Try this: Building errors
It’s about 2/3 of the way down.