Since I bought pets my gates will not give the option to lock. Sometimes my sims act like the gates are not even there and can't go thru them. I hate the paparazzi and didn't know you cannot starve them. I usually reset them to get rid of them.
I'm having this same problem: I used to have a normal gate locked on my lot (not the paparazzi gate), but since getting pets, I can no longer lock the gates! I've replaced them but it didn't help. Did they change this recently? Some people on this thread say you could still lock gates but I can't.
It's rather annoying I can't control where my horse roams. It doesn't seem logical either that the horse can just enter & leave his stall by himself. So, he ends up galloping all around the place, which I don't like too much.
EDIT: I solved it! It seems if a gate is placed on a fence that is not a perfect, fenced in area (I don't know the correct english word for this, but it has to be a "square" of a fence, with no holes whatsoever - there's a tool for that too in the build mode), it can be locked. If it is on a single fence, or there is even one hole in the fence somewhere, if doesn't give any options when clicked! I'm sure it wasn't like this before, but I feel so good for finally figuring this out, I can now control my horses. *happy dance*