Failed to launch error when using CC

I am also experiencing the same issue. I play The Sims 4 on Steam. I have tried all the suggested solutions, but the game still will not launch.

In addition, the EA app frequently fails to connect to the server, and I sometimes receive a “Application request timed out” error on Steam. When this happens, neither clearing/deleting the Mods folder nor repairing the EA app resolves the issue.

I moved each MOD folder out and back in one by one. It worked once, but now it fails 4 out of 5 times and takes over 10 minutes to load. The issue is clearly getting worse, not better. It’s frustrating that EA still hasn't addressed this.

And that update will break something else. 

The Sims team are going to fix the issue. There should be an update this week.

You're not crazy. I have been 50/50ing my cc folder for hours. Entire folders of CC that I have already tested are confirmed "working" after I test a few more creators, the first ones I tested are causing the launching issues when I put one in by itself and it was working but now all of a sudden it's not. EA needs to fix the game and fix the block against PC users trying to use CC. It is 100% an EA issue and I'm so upset because of how much time I've spent to realize I have to play with no cc or just don't play. This is actually a big fail for EA. 

For me it doesn't seem to be a problem with a particular mod, but possibly with merged packages.
I've done a 50/50 (or more like a 10/90 :D ) with my packaged mods and had the game load, then added a single merged .package file and got the error. I removed that package, and again got the error. I removed a few more, and the game loaded. Added some back, and the game failed to load.

Dear EA Support Team,

Please understand that this message was translated with the help of ChatGPT, so I ask for your understanding if any phrasing sounds slightly unnatural. I would also like to acknowledge that the wording of this message may sound strong, but I hope you will understand the level of frustration many players are currently experiencing.

I have reinstalled the game, created entirely new folders, and copied over only the necessary files, yet the issue still has not been resolved. While I understand that some Simmers have reported temporary success with certain workarounds, it is deeply disappointing that, after three to four days, there is still no clear and reliable solution for the majority of affected players. At the very least, you should have made a rollback available so that players could continue to access the game.

Minor bugs can happen, and most players understand that. However, launch errors that prevent people from accessing the game are not minor issues. They significantly disrupt gameplay and reflect a serious failure in quality assurance. This is particularly frustrating because problems of this scale do not seem to be isolated incidents, but part of a recurring pattern surrounding major updates. Simmers around the world should not be treated as your test environment.

I do sympathize with the developers and support staff who may now be working overtime and through the weekend to address the problem. However, if the update had been properly tested and prepared in advance, this level of emergency response may not have been necessary in the first place. Whether the issue lies in management, release planning, or quality control, I sincerely hope this incident leads to meaningful improvement.

I hope EA takes this major update failure seriously and uses it as an opportunity to rebuild player trust and improve its testing and release process going forward.

Sincerely,

챗지피티로 번역한거라서, 제대로 전달될지 모르겠네요.
(혼잣말) 게임 한번 하기 참 힘들다. 무슨 게임이 랜덤 가챠게임도 아니고 장난하나.

Alright for me, the person who wrote the memory boost trick was heavysent. This is what I do.

First, I moved/removed all CC mods from the Mods folder including the resource file. This allows me to get the unmodded game running again. Then in the game options, set the memory boost disabled, and also uncheck "Enable Custom Content and Mode". After that, try putting cosmetic CCs into the mods folder and run the game. It will run since the mods are not activated. Finally, reactivate "Enable Custom Content and Mode", quit the game and reopen again. It worked for me. 

I am sure 95% of the people problem's here is the game flagging all these apparel CCs as corrupted. I feel like that performance saving feature is refusing to open the game/loading those CAS mods because it's nature is to optimize the game's memory usage, therefore it is trying to mess with memory heavy mods like high-poly skins, hairs and clothes.

I have tried all but the one cumbersome folder naming suggestion since I have a lot of CC and not enough patience or time. My game randomly lets me in and then when I add a new patch of CC it fails to launch. And when I remove said CC and the resource file it fails to launch again even with the same CC it just launched perfectly fine with before. 

The direct from the folder launch does not work.

I feel defeated. 

I'm a fan of your sims, Sean. Keep up the good work.

I'm testing the 64 bit executable... but the failed to run error came up again, but less often than trying to run from the EA App or the desktop shortcut.