One or more files in the User Section may become corrupted, try renaming the User Files to make the game generate a new set. Remove anything from the Virtual Store (if applicable).Remove DCCache and DCBackup folders (sims3packs).Remove the Mods\Packages folder (package files).If deleting caches didnt help, try removing ALL Custom Content

The file may have been corrupted during the download process.

You've attempted to download and install an EA or Custom World only to have the Launcher Fail?