The longer you play The Sims 4, the more will begin to accumulate in your game files. The game auto generates files called “Caches” to help with faster loading, so clearing them every so often can help improve the performance of your game. This is especially true for those who use custom content and mods.
According to Crinrict, it’s not completely clear which files are safe to delete yet, so it’s better to move them out of the folder, rather than delete them all together. Look into clearing out your Origin cache files as well.
The following files are most probably cache files that can be deleted safely and that will help with troubleshooting.
• localthumbcache.package
• cache –> *.cache (all files ending in cache)
• cachestr –> All content can be deleted