As far as I know you cant suddently make a unbuildable tile buildable. (just what I think though, Im not brilliant)
What you can do is make a custom tile that is exact the same as the normal unbuildable tile but buildable.
But the far most easy way is to select the unit you want to build in the object editor, go to Pathing-placement requires, and uncheck buildable.
That allows you to place that building on any tile.
I'm on a page about incorrect corrections, and spent the better part of like two hours trying to get someone to understand that -5^2 = -25, not 25, and then that post had comments get reposted because that group is self sustaining, and that person was in turn trying to explain what I just explained to them. And I'm taking that as a victory
I will be AFK for a couple of days you guys hold down the fort while I am gone. I will be checking in on my phone but that will severly limit me. Be back saturday!
I just got to watch the video because even though I was there I was trying to work out tech problems with the chat since I was the social media guy so I was distracted but check it out guys the video is super fucking great!