Hi, I don't know what happened, and I think I probably did something really stupid without knowing what I actually did (because I'm technologically challenged and a boob), but after trying to figure out how The Sims 3 Create a Pattern tool works (which I failed at that), when I went back into CAS, all the patterns have disappeared; apparently deleted.

What can I do to get them back?

That is strange. Did you add a new pattern to your game that you created with CAP?

Yes, I think I did

Go take it out. You might have caused yourself the materializing patterns issue.
So patterns made in cap will do that unless you fix them. Here is a great tutorial on how to fix them after you create them with CAP.
https://ktarsims.tumblr.com/post/15...oarder-tutorial

Here is a thread on it. https://modthesims.info/t/574820

Where do Iook to take it out; where would the file be?

well if you didn't convert it to a .package and place it in as a mod. Check your downloads folder.
If you have the launcher look in the downloads for a pattern.

Nope, still didn't come back :/

I've just attached a screenshot of it. It only has 2 categories; "Misc." and "Favorites".

Remove all CC patterns. Take them out of any of your game folders.
Delete your caches.

Also, let me ask this did you install any CC that would have come with patterns. Like on a Sim or in a lot?
You might have to remove all CC. I would start with your latest CC and work your way back until your patterns come back. Make sure to clean your caches at each instanse of doing this.

When I have something like this happen I use a small empty CC world that I use just for testing. This way I can get in quick and test things. I put a lot down with furntiure and one sim in the whole world it's my tester world. So quick loading and saving to test.

Sorry, where do I find the CC's? I am a techno dinosaur so you might have to go full boomer dummy mode for me :p

So from your screenshot the one with the little star looking symbol is a CC pattern. If you haven't installed it as a sim3pack or a package it could have came in with a lot or a sim that you have installed.

These are some basic guides to help you dealing with bad CC that can cause issues:

This guide shows you what your Icons are https://sims3.crinrict.com/en/2012/...d-launcher.html
This talks about what I was saying about patterns made with CAP https://sims3.crinrict.com/en/2014/...-materials.html
This will help you if the CC came on a Sim https://sims3.crinrict.com/en/2011/...-came-with.html
This will help you find the CC https://sims3.crinrict.com/en/2011/...om-content.html

So I have deleted all the patterns and colors I could find in my download menu in the launcher, but the default patterns have yet to return. If it's because there are still downloaded patterns that still needs to be deleted, idk where else to check. If it's something else, not sure what else it could be.

I appreciate the patience for anyone who can help.

So where it says misc in the drop down. Can you click through each type and grab a screenshot? So we can see if you have anymore hiding out.

I'm surprised general troubleshooting tips haven't been given, but perhaps this post was missed because it's in the WCIF section?

Rather than looking for the needle in the haystack, you may have better luck dragging and dropping your entire The Sims 3 folder (the one in the My Documents directory, where you install mods, not the installation folder) onto your desktop.
Run the game, which will generate a new copy of this folder, and check for the issue. If the issue is gone, something in that folder was causing it and you can slowly move your saves and custom content from the desktop folder into the new folder while testing to make sure they don't cause the issue again.

If the issue continues even on a fresh game folder, something has been modified in your actual installation folder and is likely beyond manual repair.
Depending of the source of your install, the next step would be to run a repair (Repair Game through EA App, or Verify Integrity through Steam) or reinstall the game (only option for retail disc installs).

Since they said it was patterns/cap that caused the issue if it was a simple removal of the pattern they put in would have solved the issue which is why I went that route first. Totally moving out the folder and starting fresh and doing the add back is a huge task for someone that stated they were new to doing this.

So trying to go the simplest route with the issue of patterns sometimes solves it. How do I know because my dumb butt has done this with patterns I created using CAP before reading the tutorials I posted above.

Sometimes it's hard to trouble shoot someones issue when you don't get all the pieces of what's really going on. I put a mod in that I had no idea could cause such a dramatic conflit and not even understanding how this mod that had nothing to do with anything was causing such an issue. Now I have it in my do not ever install again folder LOL

Oh, I didn't mean to sound like I was dismissing your help- I'm sorry! I thought you gave great advice, I was just surprised that the thread was still coming back around after months, is all.
You were right to start where you did, but with all initial ideas exhausted generating a new game folder is the quickest and cleanest way to remove all possible culprits. Especially as I imagine OP just wants to play the game after this long!

I personally find it easier to start from a point that is known to be stable and working forward from there, rather than trying to work backwards looking for the needle in the haystack- especially when it doesn't turn out to be any of the known issues you suggested

Oh no worries!! I had been offline since the last time I responded as well. Adulting took over. I agree though if nothing posted above works then the new folder is the way to go!
It's just hard to know without knowing what else someone has installed. I once spent a whole month pulling/putting in mods to find a culprit mod. Now I'm better about isolating new mods/packages when putting them in for a trial run.