If you got the wrong Error Trap you will get a popup telling you the version you have is wrong. The only difference between the two versions of Error Trap is the version number.
I've never noticed any issues with Sunset Valley.
If you are having problems there you probably will have the same problems elsewhere unless you find out what is causing your problems and fix it.
I have problems wherever I play due to having 20 or more sims in a household. I recently decided to stop allowing my game to change seasons as I really only have huge, game breaking, issues when it is in Autumn, Winter or Spring. So I've now got it staying permanently in Summer.
In order to avoid getting Error 12 I notice how many times I've saved since I launched. I can usually get 2 or 3 saves before I get and Error 12. So when I have saved twice I think about if I dare try for a third save as it's time to shut down and relaunch. Going for that 3rd save sometimes means I lose a bit of game play as there is Error 12. My other option would be to reduce the number of sims in my household to close to 8, and reduce graphic settings.
If you want to move your entire world population to a new empty world you could use NRAAS Porter mod. I think the amount of memory your computer has is what controls the number of sims you can move with that mod. The most I've ever successfully moved is over 300.