Forum Discussion
@L1zz1eD High-End Loft Stuff is affected by the same server error as the base game; fixing it involves replacing the paul.dll file in the SP01 (HELS is Stuff Pack 1) folder instead of the base game folder. But you don't need to do that—installing Late Night gets around the error. Instead, I'm guessing you're getting the unknown error instead. Fixing this is straightforward: create an alias (icon) for Late Night in Applications\The Sims 3, alongside the alias for the base game. HELS should already have one.
https://bluebellflora.com/sims-3-packs-not-showing-as-installed/
Please also run the Super Patch (digital download version) to manually patch the game to 1.67. The launcher doesn't always do a thorough job of patching on its own.
https://bluebellflora.com/sims-3-manual-super-patch-for-mac-1-67/