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.
