I'm shaking my head in amazement -- This game was broke from the start and got even more broke with every update and EP release, but people bought one EP after another anyway.
I wasn't at all interested in World Adventures so I ignored that release, but Ambitions sounded great, so I got that one. When it screwed averything up I refused to buy anything else from EA until they fixed it. I'm still waiting, of course, but I've given up hope that they're ever going to fix anything. For their part, they can give up on ever getting another dollar out of me. I've been buying and loving EA titles since 1987, but no more. When this company flames out after decades of providing wonderful software they'll probably blame Zynga or other free game providers, but that's not the problem. Quality assurance (QA) is their problem. I'd love to continue buying their stuff for 30 more years if they would allow me to keep my self-respect by making sure their product wasn't useless, but I'd feel stupid buying anything else considering my last purchase is STILL unuseable.
In the meantime, I'm playing a MOSTLY bug-free game in the following manner:
I play with no CC. I don't know if CC is an issue - I just don't take the chance.
I play with no mods. I don't know if mods are an issue - I just don't take the chance.
I play all the families in town, so I play with aging off and I age everyone manually with the testingCheatsenabled true cheat (you could use a birthday cake if you prefer, but I find them to be ridiculously flammable). Just turning off aging solves LOTS of problems. The story progression toggle does nothing, but enabling aging causes lots of problems, unfortunately. If you play with aging enabled, you have story progression regardless of whether you have that toggle off or on. It was determined long ago that the Story Progression toggle is linked to absolutely nothing - it's a dead switch that does nothing at all.
Every update beyond version 1.11 broke the game further, so after uninstalling and reinstalling my game I used manual updates to update my base game only to version 1.11. That means I cannot use my Ambitions EP (or any other EP's except perhaps WA, which I'm not interested in), so I'm playing only the base game. This solves almost every other problem. Update 1.12 was the update released coinciding with the Ambitions release and it introduced lots of bugs that have still never been addressed to my knowledge (at least up to update 1.15 at which point I gave up on updates as a solution), such as the run-everywhere bug and romantic interactions bug and too many other game killing bugs that made me want to just quit playing altogether. Many of those bugs are in the base game update itself, and occur whether you use the Ambitions EP or not, but installing Ambitions does introduce even more problems beyond that.
There remains a pathing issue that causes extreme lag, often manifesting itself most noticeably in sound malfunction, and sometimes prevents sims from doing what you want them to do. If you order your sim to do something and they stamp their feet complaining about a car blocking their path, this is your problem. If you cannot get into a rabbithole entrance, this MAY be your problem. In my experience, this issue has caused all the above and I suspect is also the culprit of isolated instances of finding sims stuck or standing in places they shouldn't be (like Bebe Hart standing in the sky above town reading a book). I have traced this pathing issue to inactive families having a car in their useable inventory. I'd recommend that when starting a new game, that you go thru each and every existing family moving all vehicles into their family inventory (storage) where they cannot access them. Once this is done, you can prevent the problem from occuring in the first place by putting all family vehicles in family storage before switching to a different active family. However, if you're trying to address this issue in a mature neighborhood where the problem has already manifested itself, it's more difficult to find the vehicles which have ghosted (become invisible) and have ended up stuck in unlikely places (such as rabbit-hole entries, residence entries, underground, etc). Finding all those can be tricky, but if you persist with experimentation until you have them all, you'll be amazed at the difference it makes. They'll still use cars that they don't own, probably related to their occupation and rank, but those are not a problem. It's cars that they own that are the problem.
Lastly, I use Windows XP home with only 4 gigs RAM, so I have to keep my town size limited or the game will become slow, anyway. I tolerate extremely slow loading so long as the game runs sufficiently well in play. When the town gets too big I start paring down the population by killing off the most irrelevant people (usually elders, then ugly children) and limiting households to one child to make sure that the town's next generation is smaller while still continuing the bloodlines of each family.
I'm no longer pulling my hair out. You may be reluctant to play this game in the same fashion as me, giving up on all the EP's that you've wasted money on, but for me the game is still good, still fun to play like this. You may want to consider it before turning your back on the whole thing, forever.
editting: added "(at least up to update 1.15 at which point I gave up on updates as a solution)"
