Re: Sims 2 Ultimate Collection not starting up

@mikolajpatyna The most common cause for this is the corrupted cache file that prevents the game from opening. Please go to Documents\EA Games\The Sims 2 Ultimate Collection\ and delete Groups.cache and Accessory.cache files.

If this does not help, please take out The Sims 2 Ultimate Collection folder from Documents\EA Games\ and try launching the game to see if it will generate a fresh user folder.