I don't play Sims 4, my daughter does, I just manage her account so she doesn't go mad with purchases - so she downloaded Cats and Dogs last night. Built her new pet inclusive family dropped them into a starter home in Bridlington Bay* and the game never starts (permanent hints and tips).
She's got quite a few mods installed, so based on comments here I'm going to get her to uninstall all her mods and try again (as we had already rebooted the machine a few times and made sure the game was up-to-date). I'll report back if we have any success (especially if it does work and we can identify the mod(s) causing the issue.
* She also created a new test family and dropped them into one of the older regions, that also hung on loading up, so it's not Bridlington Bay specifically that's the issue.