Hi Stormi71,
It's hard to really say if you should or shouldn't play older save games. I've just gone by what's being recommended - which is no.
But if you've got a backup of them in a safe place. Then I say it maybe worth a try. Yes, definitely backup all your current saved games before putting any old game saves in. Just for safe keeping.
I've been doing a little research on this bug lately. And found a possible solution.
If you are unable to play your households this may help you.
1. Go to documents > Electronic Arts
2. Backup the folder "The Sims 4" (just in case you need it again)
3. Now go to Documents > Electronic Arts > The Sims 4 > saves
4. Delete the base save file (For me this would be "Slot_00000001.save")
5. Remove the ".ver4" extension from the file "Slot_00000001.save.ver4"
6. Now open The Sims 4 and see if it works.
Note: I did this on every save file, not just one.
Note: Your save file may have a different name, likely defined by you. The important part is deleting the base save file and removing the ".ver4" extension from the file with the same name as the base file.
I hope this helps,
MrsFlynn