4 hours of building all for nothing?

So I made an awsome settlement. Castle and everything.
Now I just spend 3 hours on putting another wall around the original wall…
When i was just about finish making the blueprint, it wouldn’t let me place slabs anymore, so I got worried.
I closed my game and restarted it.
Tried it again, no change exept a lua error.
Okay, then I’ll just let them build it and hopefully I can finish the towers when its build.
It wouldnt let me start building, when I clicked start building it did work, but when I clicked on the blueprint again it was back in the edit menu.

Okay, its ashame but ill have to use the ib command then.
Lua error again.
Now everytime I start the save I get the same lua error.

Long story short, I spend 4 hours laying out a wall, doing everything perfect, and now I can’t build it!!

Any ideas what to do?

we have seen more reports with this issue.

Save more often
[evil laugh]
MUHAHAHAHAHAHAHAHA
[/evil laugh]

No really, I save before starting to designe a building and again before starting to build it.

Best advice would be to design the wall as parts and raise them one by one, I think.