Hairs can go bad as Crinrict has a rose hair and a peggy hair on her list as hairs that have gone bad and they do mess with EA content when they go over to the dark side. Generally it is caused when the game gets a lot of coding changes and the creator never bothers to update their hair. The hair becomes like a foreing object in the game because the coding has changed the script so vastly they no longer "speak" the same language - as one possibility and another is it may have been unstable all along and just finally went kaboom. But almost any CC content can get corrupted and create problems the longer the game is out if the content is not updated once in a while by both creator and user. With Sims 3 CC has always be far less stable than it ever was in Sims 2 as sims 2 was just basically 2 d, and Sims 3 meshes are layered so it's a whole lot more to deal with - and one of the reason I decided to forgo third party content completely - as i really hate surprises like that as often it results in one having to redo everything once the objects really goes bad. An example was that little doll that turned into such a monster that only had a tiny small problem in it's scripting in it's beginning that just escalated until it not only corrupted games it even corrupted the exchange. So using CC can be a strange adventure in Sims 3 and is just not worth what may possibly happen.
But I cannot tell you exactly what went wrong other than the hair was obviously in conflict with something in the game that caused your fence and other issues to escalate and corrupt. I really would not even try to guess - but you can only be much safer if you periodically look for updates to all your content not made by EA and avoid any known bad content. If any of your content was in your game since before pets when EA did the biggest recodeing thus far, I'd say remove all that content and look for updates. As before pets CC is going to be the worse stability wise. If a creator hasn't updated it - well I'd get rid of it, but that is still up to you to decide.
The horses turning black could have been a number of things - such as a pattern or recolor you did not have in your game - as horses are basically Sims and fall under many of the same rules. If you download any pets, make sure you go into Cas with the pet and use the tools to add their skins to the recolkors and you should have less chance of getting that kind of problem. Also if they have a pattern, get that too.
Amjoie that made no sense to me as I often move graves over to the grave yard from houses - the only time I have seen a problem is if the ghost and tombstone is part of the story and should not be moved from that lot. There is a few in BB in the underground grave - but generally my game tells me that object is not moveable. Did you have moveobjects on or testingcheats on - as that might have allowed you to pick up one that needed to stay on the lot - I can't say for sure. I do know unless the tombstone belongs to that sim, do not keep it in their inventory otherwise it fouls up the ghost attached to it sometimes. But I will try and check the ghosts in some graveyards tomorrow just to make sure things are still working the same. It might even had been the update as updates have been known to create problems with ongoing games also. I will often start a new sim after and update to play a while until I feel the hood has settled down after changes. Usually then I can eventually go back to the familky I was working with - that way there seems less problems by introducing a new simmie.
Like Amjoie said, you can redo the townies - the Ambitions career made that possible.
