Anyone have any idea why this would be? I checked all the Sims3 packs with Custard and all the package files with Delphy's Dashboard and no problems show up. I've opened them in S3PE and can't find anything that would account for it. They were all created the same day with the same method. All the package files are in my Mods folder. When I go in the game and look in the catalog, only some are there. I'm stumped. Thanks.

The first thing I always check when something I've made isn't loading in-game is to make sure that the package isn't open anywhere- make sure that S3PE and all programs related to editing the files are closed, because if they're still accessing the files the game will not load them. Restarting your PC can help ensure that it isn't something running in the background.

If that fails to resolve it, temporarily remove all other mods and CC and test just the files that aren't appearing.
If they do appear, you likely had conflicting files- either among your own creations or with other content you had installed.
If they still aren't appearing, you'll know that it's more likely to be an issue with the individual pieces themselves, such as missing category flags.

Thanks for the response! I think what happened is I cut corners when making them. I wanted a bunch of paintings with the same frame so I just kept using the same file, exporting to a Sims3 Pack and then using the same TSR file with a different picture. It seems like it should have worked since they were all being exported to separate Sims3Packs before I went on to do the next picture but it seems like it didn't. I tried making a couple starting fresh each time and those showed up fine. Hopefully that's what it was. Thanks for the suggestion about making sure all the related programs are closed. I think they were but it's something to watch out for.

They are separate files, but they have the same instance when you do it that way. So what was happening is that they were all conflicting with each other, and as is said in Highlander, "There can be only one." :P