Well, I just found two threads posted almost a month ago with the exact same problem as this, and no responses... that's not encouraging, but the rules say to make your own thread, so here it is:

So, like two hours ago I started making a new house for my main Sims. I was just about to save it in case something happens, because I've made a lot of progress. I was dragging and dropping color palettes to make things match, and I mis-clicked. I was trying to collapse all identical materials on the item, but I think I accidentally clicked the x to close CAS. This is when I decided to save, but when I tried, Save was grayed out and said "Return to Edit Town to save". So I tried to get out of CAS, and that's when I realized the Buy and Edit Town modes were also grayed out. Then I tried editing the style of something, and when I clicked on it the sparkles came out and it did the loading icon, but then stopped and didn't bring up the CAS window. It won't do it for any item. I tried random commands to see if anything would snap the game out of it, and when I pressed ctrl+z, the Create a Style window that just lets you pick other pre-made styles appeared. I can now select other items and pick out other styles, but I still can't get out of Build Mode, and I can't make that window disappear.

So now, I can't get out of CAS, I can't edit anything, and I can't save the house I worked so hard on.
Please tell me there's a way to fix this. T_T

In order to better solve your problem, please go through the following as listed below:

• Sims 3 - Loading Crashes
  If your game is crashing on load, with or without an error message, or the game starts up then just disappears, then you have a loading crash.
  
  Please see the following FAQ and go through the steps listed in order to try fixing your game: Game_Help:Sims_3_Loading_Crashes^wiki.
  

If there are files in "CurrentGame.sims3" folder, you could copy that into your Saves, rename the folder and see what you can salvage before the screen froze.

Corrupted pattern? Did you make a note of the CASt category or it froze in any/all category?
Try those 3 fixes on a new game.



On occasion you might be asked to do a long FAQ - please make sure you do all the steps and don't just skip over them. You'll often find that these long FAQs have all the details you need. If nothing in the above FAQs fixes your problem you may post again detailing exactly which you have done and which steps failed.

The screen didn't freeze. I could still move around and select items, it just didn't do anything it was supposed to. And it isn't a loading crash, unless you count the second it's supposed to take to bring back the original item you were editing after clicking the x on an item you were trying to apply the texture to. Actually, it didn't crash at all. The game didn't freeze or close. I had to exit it myself, and I was able to do this the normal way, without having to manually end the process. Maybe I'm wrong but I thought a crash was when the game stopped working entirely... It was working just fine, except that several elements had disappeared, making it impossible for me to save, or do anything other than customize items using pre-made styles.

That said, it has only happened twice now. Once when I was applying a color to a custom window(and I had edited windows that were the same custom object without this happening in the same game session), once when I was applying a color to a non-custom fence.

I'll check out the link anyway...

When you were changing the window and fence colors, were you in the same pattern category?

That wiki is still applicable even when the game is not crashing, it is the quickest way to determine if you have
- corrupted caches,
- corrupted CC, or
- corrupted User files.

If fix #1 is OK, you had corrupted caches.
If fix #1 don't work, and the issues are gone using fix #2, then you had corrupted CC, which now leaves it up to you to determine which...and so on. I'd target the patterns in the category that causes the glitch, first.

Alright.. but how do I know if the fix worked? This doesn't happen every time I copy colors from the same category, or onto the same items. It might look like it's fixed but then happen again at just the wrong moment.

how do I know if the fix worked?
Uh, when you're no longer stuck 100% of the time while in CASt?

If it still occurs after removing *all* CC patterns, it might not be just limited to that CC type. That's why the fix#2 was suggested - to rule out all broken CC.

Have you tried Delphy's BlueLotFixer? It can fix some broken/bad CC - in this thread, page#25 post#613 http://modthesims.info/showthread.p...25#startcomment

I'm having this problem.. and its four years later... Can't find any help with this anywhere.. I wish Sims had a "cc" command like fallout to close all windows, and return to game..

On april 2015, i have a similar problem : when i attempt to load the create a style, it loads indifinetly and i must kill my game to sort this thing out. Can't use this anymore (i've already tried to make a new profile).