I installed a bunch of hacks all at the same time just as you read all the time that you shouldn't and I paid the price.  Suddenly none of my custom sims were showing up.  I first tried taking out all hacks but that didn't work. Then I uninstalled and re-installed everything which we all know is a pain, but that didn't work either.  What finally worked was I did fix on regedit and apparently there were some corrupted entries and some items that were referring to files that no longer existed.  So if you're having trouble and have tried all the normal things you might want to fix up you register.  Thank goodness that worked for me because I just don't enjoy playing the game without custom content!

I was having a lot of problems with AL so I uninstalled it and re-installed it.  I did the whole backup thing and that worked for my custom objects but I have no more custom sims, that window is empty.  I've tried re-installing them but they still don't show.  I've got the settings set up correctly to show custom content, I've deleted cache files, etc. and nothing works.  Frankly, other than a little fun I had at first with witches, I don't really like apartment life so I guess I could just uninstall it but before I go to that extreme I thought I'd see if anyone has any ideas.

I've always known that you invite problems when you download hacks but I've always downloaded custom content and even object hacks and haven't had any problems.  Recently because Apartment Life has been frustrating in so many ways I downloaded some game mod hacks and have had tons of problems.  I'd like to delete them out of my downloads folder, anybody know an easy way to find them since most of them are named just a bunch of numbers and letters?

Can't Wash Dogs
I don't know if this is just from Apartment Life cuz I haven't played any families with pets for a while but I even deleted all content that I had installed in the last week but still can't wash dogs. The sims start to go through the motions and then suddenly the option is no longer in their queue.
 
Can't use expensive telescope
since installing Apartment Life my sims go to use the telescope and then stand up straight as if they can't access the telescope. It's not a custom content telescope just the regular one that comes with the game. The cheap telescope still works so what I've had to do is when a sim "wants" to buy an expensive telescope I just buy it and put it somewhere they can't get near it and use the cheap one to stargaze but it's annoying.
 
Butler burns food
I have a couple of houses where the butler always burns the food. They all have the best fridges and stoves and the fire alarm but that doesn't seem to help. I was thinking maybe I should fire him and hire a new butler maybe? Anyone else have this happen?

I've got a couple of butlers who always burn the food when they cook.  Anybody know a fix for this?

I think you should be able to switch between families that live in the same apt building without having to wait for the loading time of exiting to neighborhood then reloading the apartment and selecting a different apartment.  I still don't think there is much of an advantage of putting families in the same apt building.  If I want certain sims to get to know each other easily and be friends, frankly it's easier to move the sims into the same house and then when their friends, have them find their own place.  I like the witches and butlers but haven't really had much fun playing the apartment buildings.  And it's really annoying that you can't build buy in common areas once people have moved into a building.