Ideas
Having this issue too. Long term Legacy save. Have mods, but this is occuring without the mods installed. Lot was formerly a restaurant. Bulldozed and then bought empty lot. Built and furnished it as a residential. First noticed something weird when i went back in to change some furnishing and realised it was giving me infinity money even with a household moved it.
Went to switch it to small business and couldn't do it from the BB but could from manage world. Then it gave me the same "no lots" error that people are giving.
This save has previously had mods (MCCC, UI Cheats, No phones while walking mainly) but these errors were replicated with no mods and then just with better exceptions.
The exception that is occuring is here
Exception in <function buildbuy_session_end at 0x00007FF4B7E10170>, args: (847541125484335303,), kwargs: {} AttributeError("'NoneType' object has no attribute 'funds'") (AttributeError: 'NoneType' object has no attribute 'funds') Trying some of the tips people have suggested has resulted in me not even being able to bulldoze the lot.
The played family also does not even appear as living there on the map view, unless i go to build mode, then go back to manage worlds
If i load my build from the gallery, where it is a small business, and select that option it still imports as a residential and i can't change it to anything other than the residential options from the BB menu after going to live mode. I could change it to a small business lot type from manage worlds, but i get that exception and can't register the lot after i have done that.
All of this happens both in a new save as of this file and after i have repaired my game.
This was my first attempt at playing with BH too.