Oh dear I've missed another one. Sorry, Penelope...

The game does make log files if it crashes, stored in My Documents\EA Games\The Sims 2\Logs. However, I have found those to be quite worthless for me so far... even if it did include the interesting information among all the rest of the noise, it wouldn't display the culprit file, which is what you need to know to delete it.

Your problem does sound a bit like a corrupt download, though, and if it persists after you delete the suspected file, it may be a cache problem.

Have you tried deleting Groups.cache and company? When I have a problem like this, I go to My Documents\EA Games\The Sims 2\ and delete the following three files: Groups.cache, Accessories.cache, and cigen.package. You will only have Accessories.cache if you have Pets or later EP. You may not have cigen.package if you have never used BodyShop. If you are nervous about deleting files, just move them to another directory for safe keeping, but the game will regenerate these files next time it needs them.

If that doesn't do the trick... If it's a problem with the thumbnail image in the catalog being corrupted, you can try deleting the thumbnails cache. I have never done this but I've read it's safe. However you may want to move the file out of your Sims directory rather than literally deleting it, in case it breaks your game worse. (Don't blame me! ) So, the thumbnails files are stored in My Docs\EA Games\The Sims 2\Thumbnails. Logically the one you want to remove is probably ObjectThumbnails.package. Then when you go to the catalog the next time, it should be slow every time you advance to the next page since it's regenerating all the thumbnails, but at least if you had a bad one from that file it should be fixed.

Let us know how it works! Hopefully you have already fixed the problem on your own, but this info may help someone else too.

Oh, well! That is a shame, but at least you can access everything by clicking on All.

Personally I have a weird crashy bug where the game sometimes exits abruptly when I put down that Moroccan-looking door and attempt to turn it to the face the other way. (I like having the doors open in the most logical direction, I am detail-obsessed that way.) I now save quite often while building, since I use that door all the time. I lost a good hour of work on Acanwald that way, though.

I wonder if it's because you had downloaded a light that was cloned from a Uni light? I think I have always had the game crash during loading when I had stuff from the wrong EPs but who knows?