I've recently got a new laptop and installed my game and CAW, and everything seemed fine. But now whenever I open up a world in CAW and click to edit in game, it just won't open: for a couple seconds the screen where you view your world gets blue and it seems like it's gonna load, but then it goes back to the preview and nothing happens. No launcher, no loading screen, nothing. I don't have EA or Origin installed, so I don't know what's causing it.

Which gameversion are you running? This thread might give you some help:
https://modthesims.info/showthread.php?t=441595
(there is some discussion about EIG issues toward the end of the thread, plus a link to a batch file to launch EIG independently of CAW in the first post).

Also this thread might be useful:
https://modthesims.info/showthread.php?t=640633

I have the 1.67 version of the game and the 1.67 version of CAW. I've tried clearing out the cache files, re-installing it, tried doing a clean-game install and nothing. I even tried opening with SuperCAW and the same thing happens. When I try opening EIG, the screen goes blue like the first pic for a second and then goes back to the game like in the second pic. No pop up, no error message, no launcher opening, just... Nothing.

Try running CAW as an administrator. Also try the batch file:
https://modthesims.info/showthread.php?t=453161

Tried running both CAW and SuperCAW as an administrator, same thing happened as before. The batch file didn't do anything, as soon as I paste any world file in it, it closes without doing anything. My Sims 3 game itself runs fine, so I have no idea why EIG won't open.

Tell me a bit about your setup- what CC/ mods do you have installed? Where do you have the game installed to? If you are on 1.67, I can't think of any reason why it shouldn't work.

1. I've completely removed all CC and mods from my game to try and make it work, and did a clean install of the game just to be sure.

2. The game is installed in C:\Program Files (x86)\Electronic Arts\The Sims 3, and CAW is installed in the same folder as C:\Program Files (x86)\Electronic Arts\Create a World Tool

3. I never had Origin or the EA app installed. I've installed the game and a few expansion packs (WA, Ambitions, LN, Generations, Seasons, Showtime, SPN, UL, IP) and stuff packs (70s, 80s and 90s stuff, Luxury Suite, and Outdoor Living) through a CD. I've tried emulating the disk and then not emulating, just to see what happens, and nothing changed.

I'm thinking maybe Windows 11 might be blocking the EIG pop-up screen, or maybe an antivirus. I really don't know. Back when I first installed the Sims game, it did the same thing after launching (I would click to open up, it would seemingly load for a few seconds as a completely black screen and then it would close the game entirely) and I figured it was probably because the game was opening as a full screen program, and I fixed it by having it open as a window directly by altering the game file properties in the C:\Program Files. But frankly, I have no idea if this is what's going on with EIG, or how to fix it this time.

Try adding it (or the installation location) to your exclusions list in your antivirus. If that fails, the only other thing I can think of to try would be to install it to a different location (make a folder in the root of your hard drive, such as C:\ Games\ Electronic Arts and install there, as this will avoid UAC or virtualisation).

I'm hoping others might have some ideas too, is anyone reading this who has any ideas or experience?

I've tried it and nope, still nothing. At this point, I'm just baffled. Meanwhile, I've exported my current world and it opens on the normal game just fine, I'll edit in there the lots I'm building, but thanks for trying! If anyone has any idea how to fix this, I'm interested.

Oh dear, sorry you've had no luck! Hopefully someone else will have a good idea- I'm still using Win 10 on my PC until I can get my arse into gear to build a new one, so I haven't tried CAW with Win 11 yet.