I have this problem too, tried to used modded launcher too, or game without any mods, but nothing worked.
From my perspective the problem has really trivial cause. After clicking "Edit in game" button, Create a World Tool tries to open the game directly, by skipping the launcher. Origin had added that program to exceptions and allowed it to open the game by itself. EA app doesn't have this program in exceptions and doesn't allow it. When I try to use Edit in Game mode, CAW tries to open the game and skip the launcher, by then EA app interrupts it, stops the process, and then launch the game by it's own basis just regularly opening the launcher. So the right process which was supposed to happen, was just broken in meanwhile.
I don't know if adding this program to exceptions in EA app resolve all the problems, but it's worth to try at first place. Don't know how if EA app and Origin are similar in coding, or are on competely different engines, but developers should check out how it was resolver in case of Create a World Tool. Cause Origin allowed to use it and launch the game with it's own method.
CAW is located usually in:
C:\Program Files (x86)\Electronic Arts\The Sims 3 Create a World Tool
but for odd reason, folders are named in different way for each language version. For example, for polish language version the path looks like this:
C:\Program Files (x86)\Electronic Arts\Narzędzie The Sims 3 Stwórz świat
...
But the thing that doesn't change, is inside of these folders. Create a World Tool is simply called "CAW.exe" and as I said, it's located in these path above. Maybe players playing in other language versions will paste the exact location in their case too. What I try to say, is that it's worth to start here and add "CAW.exe" to exeptions, so EA app would allow it to open the game on it's own way (without the launcher), to simply edit the worlds and let simmers end their long term projects in game.
Hope I can mention there EA's employees @EA_Cade
After reading EA_Cade's comments here , I started wondering if the best (and potentially easiest) solution for EA would be to release a build-mode-only version of TS3 for world developers. I mean, we don't need the full functionality of the game for EIG work. And build and play modes operate from different (albeit connected) code cores, don't they? Maybe it could be possible to snip them apart and put out a build-only shell engine to work with CAW.
Of course, I have limited programming experience and maybe this wouldn't be an easy thing to do. I just feel like this shouldn't be as complicated as EA seems to be trying to make it.
@natashajones615 I think you figured out something, but my feeling is that they won't do what you've just asked.
I'm going to throw out a theory as to what I think happened with EIG and the EA App. I believe that this was all by design--not for malicious purpose; instead, out of misguidedness.
I say that because I've seen that over the past several years, there's been an industry-wide trend in the tech sector to force users into these highly restrictive ecosystems for some reason or other (safety issues, licensing, etc.). These ecosystems have become so heavy-handed that they're now crippling programs and in some cases hardware on people's systems.
For example, longtime simmers remember the frustration of Microsoft putting out an update that crippled Sims 1 in Windows 7, then completely killed the game in Windows 10. I have had software (not gaming but vide editing) suddenly get crippled when the manufacturer dropped support for codecs. Microsoft also released Windows 11 demanding something known as TPM, now cutting off millions of users who are still on older machines.
My theory is that the whole point of EA App is to force users to migrate to this restrictive ecosystem for security and anti-piracy measures, and that for whatever reason, they just don't want EIG baked into the App.
