Launcher won't come up, taskbar icon disappears.

@burcincokokrem  Please move your entire Sims 3 folder out of Documents\Electronic Arts and onto your desktop.  When you open the launcher, if it opens at all, a clean folder will spawn with no content.  If you still can't play, please take a screenshot of this new folder; I'd like to see whether the typical files are all present.  And of course let me know if no new Sims 3 folder appears at all.

Additionally, as a test, try launching Sims 3 without Steam and without the launcher.  You can do this by double-clicking TS3W.exe (with the W), which is inside the game's program files.  Unless you changed the install location, the full file path will be:

Program Files (x86)\Steam\steamapps\common\The Sims 3\Game\Bin

If this doesn't work either, please run a dxdiag and attach it to a post.

https://help.ea.com/en-us/help/pc/how-to-gather-dxdiag-information/

I tried to move my sims 3 folder out of electronic arts and launcher fixed. I could open launcher after it. After I install my ccs via launcher, the next time, same thing happened again. I have 9000 CCs, maybe they cause it? How can I detect that which one causes this? By the way, The game runs without launcher normally, and ccs don't make any trouble in game. Only launcher crushes...

@burcincokokrem  The launcher is sort of fragile and can crash when you have bad custom content, or sometimes just too much cc.  The way to find out what the problem is is to install your cc in batches, not all at once, and test after each batch.  That means restarting your computer and trying to open the launcher again: sometimes it works right away and then doesn't later on.

Each time the launcher still works after a test, you can make a copy of your Sims 3 folder and set it aside.  If the next test goes fine, great, trash the old extra copy and make a new one.  If the launcher stops working, you'll know that one of the files you most recently installed is a problem.  You can then use a copy of the backup Sims 3 folder (keep one copy set aside) to reinstall those recent cc items one at a time.  Once you find the culprit, you'll know not to install that particular file.  Please keep in mind though that you may have more than one bad cc item.

Or you could just bypass the launcher as described and not worry about it.  If your game itself is fine, the launcher is extraneous.