This patch has destroyed my main save of almost 7 years. I am also having this issue amongst many others since purchasing for rent. I play with mods (limited and always kept up-to-date and very tidy) so I was reluctant to post this but I'm not seeing many other reports on this.
I didn't attempt to build on this lot or even visit, I just noticed when on map view my lots in the fashion district show as incomplete and doesn't even show a lot type, when attempting to go into build mode on the penthouse lot nothing is there at all.
The lot is not there, the grid is gone, doesn't allow me to build anything at all. I tried placing a lot from the gallery and nothing happens.
Meanwhile, the other lot in the fashion district has somehow reverted to the original lot that came with city living (without me even visiting or building there at all)
Truly at a loss and regret buying for rent.
UPDATE: Building in live mode replicates the same bug as OP. (Floating Building)
they finally fixed the bug with the latest patch on a new save.
but my old save is completely destroyed, the lot remained floating after putting a new build and bulldozing and all. so frustrating to say goodbye to my old save i kept for years
