Hello again! So I wanted to check back and let you know that you were indeed correct (of course you were!) about there being too much stuff on the lot of the particular save I've been trying to load.
I accessed the lot by loading the game via "Load Saved Game" (as opposed to "Resume Game") and deleted a big deco garden full of CC I built last time I was able to play - I think that's what sent the lot into "too much stuff" territory (sucks that this bug exists, but at least we found the root of the problem). After I did that deletion, I saved the lot, exited the game, deleted my localthumbcache file, and then started the game again. And what do you know - THE SAVE LOADED and now I'm playing it for the first time in a week! Woot!
Anyway I just wanted to thank you again for your help and update this thread for anyone who might be having the same issue. I'll be more careful and choosy from here on about how much stuff I add to my lots (I'm a huge fan of clutter)!
