Crashes in "The Sims 2" are caused by custom content, problems with the game itself, or unrelated issues with the player's computer hardware or operating system. Simple steps such as clearing caches and disabling conflicting custom content solve many game and content-related crashes.
Clearing cache files allows the game to rebuild clean files the next time it runs. This easy step resolves some crashes caused by the game itself, particularly when the game refuses to start or crashes immediately on startup. Antivirus software is another common cause of startup crashes; temporarily disabling the antivirus and attempting to run the game immediately helps determine whether or not this is the issue. If the game runs while the antivirus is disabled, it means the crash is being caused by an antivirus conflict.
Game crashes that occur only in buy mode or build mode are often caused by custom content. This is due to two or more pieces of custom content conflicting with each other. Custom content conflicts and issues are found by running third-party software used by content creators, such as SimPE. This software scans the installed content and informs the user of conflicts. If this software is not available for use, the only other way to determine the issue is by disabling modifications one by one until the problematic content is located and the crash no longer occurs.