Since a few weeks, I have the same problem. Whatever save I trie to play, after some time spent on playing, all the neighbourhood lots are shown as their default version. The lot I play in works most...
Ideas
Status changed:
New
to Under Investigation
Currently keeping one thread for all lot corruption issue as there's many symptoms to what's most probably the same underlying issues.
Please see this for possible symptoms: [OPEN] Houses/Lots disappear