If you try to launch the game from another EP/SP or the base game you get the Unknown Error message.Īmbitions, Fast Lane, Late Night, Outdoor LivingĪll those downloading and installing the digital versions of the affected packs through Origin.ĭuring the installation process the add on pack alias (shortcut) is not being added to the base game Application folder so the game cannot find it. You have just downloaded and installed an Expansion or Stuff pack through Origin but the pack is not showing up in your Applications > Electronic Arts > The Sims 3 folder.

Get yourself comfortable before doing this, depending on how many EPs and SPs you have it may take a while! You will also need to probably follow those instructions in order to complete the installation successfully. This is related to, but not the same as, the other Unknown Error message whereby files need copying from one EP to the other.

If your installed Expansion and Stuff Packs aren’t showing as installed in your Applications > Electronic Arts > The Sims 3 folder and you are receiving the Unknown Error message then you need to follow the instructions below to get your packs working properly.

Sims 3 addons