I've downloaded the clothes, put them into the Mods folder, resource.cfg file is there, but the custom content isn't showing up in game, which is weird. Any help?

same for me. They are all in my mods folder, but they arent in my game???

Check under Options --> Game Options if they are enabled.

Did you put it in subfolders ? Do you have now package files in your mods folder ?

I have been trying the last three hours trying to get custom content to download for my game. I do not have any sub folders in the mods folders and custom content is enabled in the game. They are all package files and I have been putting them into my mods folder but they are just showing up when I check to see if the custom content is being shown but it is not. I download custom content from tumblr, the sims resource, and my sims 4 blog. What should I do now?

I found a solution and I was having the same problem. In my Desktop I had Sims 4 mods, but it wasn't actually installing into the game itself. Here's what I did: Search up "Electronic Arts" in your computer. Find the folder, and go to your mods. You'll notice that some of the mods you tried to install aren't in there. Download whatever you want and put it in there, make sure Sims 4 isn't open while you do this. Find the "resource.cfg" and delete that, don't worry, it will not mess anything up. Close your folder and then start the game up again. Your mods should be installed! Hope this helped!