Whenever I try to use CC Magic or compressed packages just downloaded from anywhere, the files don't appear in-game, and I'm not sure why. Does this have to do with resource.cfg or something? I've followed instructions to the letter regarding CC Magic, I'm fairly certain. I've tried deleting the cache files, which doesn't help. All other custom content works, both normal packages and sim3packs. It's just when I try to compress stuff, it stops working.

When you say compressed packages, do you mean you've zipped them up with WinRAR or 7-zip? Or have you merged them with S3PE? I use merged packages all the time in CC Magic without any problems but have never had much success with zipped ones, despite the fact that CC Magic is supposed to be able to work with them.

Another simple reason why items may not show up in game, is if the set hasn't been enabled on the Configurations tab within CC Magic. If you've created a new set for these packages, make sure it's in the right column on that tab. :-)

Yeah, I mean merged. They're unpacked from the zipped file.

I did move all the packages and enabled them in CC Magic, but the result was exactly the same as when they were disabled. Dunno.

Do the package files work if you don't merge them? CC Magic will actually merge them all by itself. That's one of the main benefits of using the program. There really isn't any need to merge them manually first. I only do it because I like to merge 'sets' together but it's really not necessary. If the package files still won't work even without being merged, I would say there could be something wrong with them. Corrupted maybe? Perhaps try re-downloading them from their original source if possible?