Infiniate Cas ,Icon Loading Loop * Desperate plea for help*

That sounds like a LOT of CC but when I have an issues with my CC not loading/giving me issues, I'll take a few days(usually due to work and stuff it spans over a few days) and sort through it.
Basically, I take all of my CC out of my Mods folder, make a new Folder in my Downloads, and put things one at a time into the game again, to pin point exactly which item is giving me issue. It takes a long time to put an item in, and take it out, to put the next single item in and so on and so on. But hopefully then you can find the problem item!

And just so this makes more sense, I'll provide an example below in steps haha
1. Take ALL CAS items out of the Mods folder, and place into a New Folder in downloads.
2. Take one item(let's say a dress), and bring it back into the Mods folder.
3. Open game, find item. Does it work? Cool.
4. Close game, put the dress(or whatever item) into a different folder than the one above.
5. Repeat until you've gone through every item.

Hopefully you find the file causing the problem!

Sometimes my CC lags my game right after an update, maybe there's a repair option on your Origin homescreen(if you use Origin, I'm not sure). Sometimes running that may help?
Other than that, I'm not sure and I'm sad for you if you have to lose a bunch of CC :(

The loop returns and ive removed upwards of five gigs and completely remerged fresh files so im so confused as to what is causing it and the hunt continues. Is anyone at all had a similar error in cas with this infinite ui thumbnail load loop?

you can retrieve your cas items from before you ran the delete custom thumbs in the sims studio back up folder for starters. I made the mistake of deleting thumbs once, i can't imagine why its needed unless someone wanted to customize all thumbs but i cant do that for 6 gigs of poo lol. I had to toil away for literal hours to find my problem. It ended up being two things a shirt whose mesh had to have been borked, i forget the maker but it was a female shirt. The second thing was something I had frick frack made which is why my arrogant ass didnt check it because ive never had a cc i made not work before lmao it was a damn skin for a toddler but it was before the sims studio was totally working so I am guessing that was why. I also had an issue with a merged file of hairs after the patch. I would suggest always making a back of your cc folder when it is in working order at least once a week . Updates will always be a headache though every time , it's just part of the "joy" of cc. I now i have merged and unmerged copies of all my cc and do this once a week and organize everything but creator, theme, and time downloaded and i STILL can spend hours finding a finger nail that the game just can't comprehend. It amazes me is capable of breaking it lol. the only method capable of finding it without fail is the fifty/fifty method but with a lot of content its still very time consuming process. when doing the fifty try to arrange the folders by recently updated so you can check the folders you put downloads into recently first. Always batch fix stuff in studio so they work properly in game like counters, beds, mirrors and lights and if at all possible try to avoid having cas cc for random townies. Sometimes that causes problems when trying to pin point an issue. Also pay attention to the last thing you click before a crash or a lag .For example that is how i found the shirt was broken, whever i clicked it the load loop would start but i had to do that FOUR loads before I finally caught it cause im slow as poo. Anyway I hope you find the problem I know it's a headache . I know there is never much people can do for me when I post these I usually just need to vent and plead for help to make myself feel better lmao.