Mysterious error 12.[SOLVED]

I have few saves in my Sims 3 game, every save it`s one of towns that I have.
In Bridgeport I have a lot of families, built there park in celebrity part, played for hours and never got error 12.
In Twinbrook I did bar from the Red Randevous, built wedding park, my sims from there travelers and very fine went to France/China/Egypt many times, had bachelor parties and I always able to save and never got error 12 while saving.
In Appolusa Plains I have disco club that works just fine.
In Lunar Lakes I built beauty saloon myself, have a sim that working in him and again all fine.
In Hidden Springs I did disco club from one of hangouts, played many families (even families from the exchange), have a sims that join careers from ambitions and never got this error.
Mystery starts in Sunset Valley save. I played few families just fine and then decided to give them some bars and clubs. I built disco club, sport bar and pool bar myself, replace lots from ambitions on ambitions lots that come with pets, place hangout from Sweet Treats and few generations and ambitions houses. Then I try to play my active family (it was Andrews) and got ERROR 12. Next day I changed household (very not first time in this town) and open new family (it was a Working friends). I was able to save like 6 times that got the same error (plus to this game slow down very strong way).
I use only store content from games4theworld, have few fixes (like for the deep fryer) in mods folder. but I`m sure that problem not there. I cleaned cashes yesterday and read a lot about this error. But when I play another town I never get this problem. Can problem be in venues that i made? I didn`t try to remove them still. Does any one ever had the same problem? I`m pretty sure that it`s game problem, cuz I had problems with Sunset recently when I had Show Time. My sims just watch empty stage in time of sim fest and then game crashed, but in all other towns all was fine.

And in Sunset Valley I have no one celebrity (in all other towns they exist). I never play with story progression (I really don`t like her). In bars that I built working homeless sims (like Sunny Backshi), but party dancers from generations all are new sims.

It`s really helpful, thanks. In other sites I don`t found anything like this. But I still have a few questions.
If I will move my families from Sunset to new Sunset with porter and place houses and bars again, can`t it bring to the same error? Or sims in Sunset can`t have bars and clubs? I still don`t have generations there I played 4 families (about week of sim days every of them) and make only one my family, but didn`t played that household at all...
And if I`ll use porter to pack my sims does it will replace them in new Sunset when I`ll unpack them? They all ready Sunset families.
In my save folder I still have backups of my deleted saves. Should I remove them?
I remember that I saw new big Sunset Valley on some sites, maybe try to install it? This problem happenings only in Sunset, in Bridgeport I have more households, and played that game longer than Sunset...

Thank you very much for help. Will try to use Porter to save my game and making back up next time.

I made copy of my families and created new save, after this game run much more fast and error still didn`t appear. But I got new problem - my game start crashing in Edit a sim mode. I decided to fix it and start uninstalling all store content that I never use. Some objects that were in game I can`t find in my launcher, and some of objects that were in launcher never show up in game. I uninstall a lot of objects, some packages that were in installed items. And now when I wanted to uninstall some window, door and barn, I got this message

Rustic Barn error - cannot uninstall package with depends.

But I really can`t remember them in my game. And in my installed content I can`t find Hidden Springs, but I played in this town! And Lunar Lakes in launcher as it must be.

//EDIT

Ok...I cleaned my store content yesterday, installed few stuff packs
that I hadn`t before and it`s help me with error with CAS and Edit a
Sim. By the way I found ErrorTrap mod, I`m sure that it`s exactly what I
need, cuz my game have really a lot of glitches and bugs. But I`m
little confused that in Twallans site two version of it - one is for
games downloaded from Steam and for everyone else (either physical DVD
users or digital downloads via EA's Origin service). I have DVD with
base game all other I got from torrent and using cracks and fix. Can I
use this mod? And what is the version that I need?

Lady ElDi,
I got this mod and now my game works fine. Maybe exactly glitches was the reason of error 12. Now with the errortrap my game runs faster and even don't slow for a few seconds as did before.
Now no more questions.
Thanks a lot!