Sorry for the bump but this is ridiculous. Months and months have passed and this problem hasn't been addressed. Seriously? Old builds I have made don't work anymore if I plop them in. Several Maxis builds have what are now impossibly placed objects on diagonals. I came out of a long building hiatus so I thought this was a recent problem but no!
Also I am not using the move objects cheat, I never use that cheat and am not going to because you broke your own game.
Has this been fixed with the new patch? I did not read anything about it in the Notes and I cannot get into the game myself to test.
Just tested—this is still an active issue. Also, beware of loading/visiting lots or apartments with diagonal walls. Objects that are considered to have invalid placements would be automatically removed without notice. I just had an empty community gym’s showering area because the plumbings were originally attached to diagonal walls.
This has been the case for as long as I can remember, but the "bb.moveobjects" cheat allows the placement on diagonal walls.