I was working all night on another skyscraper, this time for the singles in Downtown. By mistake I started it as a community lot, but I changed the lot zoning to residential and downloaded the mailbox and garbage bin and set these up. I tested that it converted into an apartment and back. Then I added more floors. After finishing the fifth level, I typed setHighestAllowedLevel 9 to continue building - but it did not work. I have tested it on two test lots, and they build up fine. So either it is the past as community lot, or the fake mailbox, I guess. Or it could be because it was a packaged lot. In either case, I either have to play it without a roof (and shorter than intended) or start building from scratch again. It was fully furnished and all, to get the correct rent and for the benefit of visiting the neighbors. Next time I'll not furnish it until I have built the skeleton to full height. I may not even add interior walls until I get the outline right. Live and learn.