So i have a template that does this. one i made yesterday.
Im on latest alpha buiild ( release 663)
bit background story here. was making this building and i ran in to a bug i had a few times before that will prevent me from adding any blocks to a building. Normally i can fix this by just making a save and reload.
So i did that but still cant add to the building, so tried to save the half finished template so i could remove the building and place it again, but i just get the few walls and windows placed from the template.
When i logged out tho game updated.
https://drive.google.com/open?id=0B7Sa8ogmH3qhMEo2ZTBqbGprd0k
theres the template i tried loading a new game and place it there and got same issue.
i also included the save game with the building where i cant add on it. As in before i made it in to a template.
(save game gets an startup error caused by the large castle, if you remove that startup error goes away, its reported in another post)
playing a bit more around with the building before i made it in to a template i can still delete stuff on it.
but if i attempt to add slabs to it. building mode locks up completely and wont let me do anything.