Been having this exact same issue, which sucks because I was so excited to play with the new pack. I don’t even have mods in my game at the moment and it happens, so it’s definitely not mods.
I'm having the same issue -- with and without mods (and I've been adding mods to sims games since TS2, so this isn't me not updating something or having a stray file hanging around; I mod responsibly), where I cannot enter Copperdale at ALL. I can't live there, I can't travel, and it's not throwing any kind of error that BE or MCCC might catch so I could go in and fix it. I've tried using a repaired vanilla game, a reset of the game without mods, and an uninstall/reinstall -- and still no Copperdale. This really needs to be addressed sooner rather than later because this is not only game-breaking, it's ridiculous that we all paid money for a expansion pack that isn't expanding anything.
