PC Singleplayer Revision (#94750/17645) Building Bug - my structures collapse when I sign in

So I’m playing singleplayer and I’ve been building on this castle in admin mode for 2 days now.

And I get this odd and upsetting bug: I try to build a part of my design (a tower on a ceiling floor) but if I log out and then log back in it just collapses?? Always in the same spot, if I try to build on other sides of the building everything is in place. I should mention I used Shift+Del to delete walls and whatnot.

I have no idea what to do, I want to finish my project but nothing seems to get the bug solved. I restarted the game, I deleted the entire ceiling underneath the structure and tried to rebuild but I still get the bug. Need to mention that I once finished the whole thing and it saved but I made some mistakes with Shift+Del when deleting stuff and had to rebuild, I seriously don’t think it’s from that though.

Anyone who can help me out?

try checking the stability of the peices your placing with a repair hammer it sounds like for some reason those peices arent getting enough support. had a similar issue with one of my houses and had to build some extra pillars to solve the roof randomly caving in

Same thing is happnening to me twice now ,building has collapsed ,chests and other things i have put out all gone,before hand everything was fine,this has happend sence the last couple of up dates ,so was worndering
is the any conection to the up dates causing this to happen . It’s putting me of building again and even playing till this is sorted out,

any help on this would be gratefully accepted