Okay, so Showtime just came out today in N. America and of course I had pre-ordered the collector's edition.
After waiting 2 hours for the obscenely slow Origin to download the expansion I cleaned out my custom content, updated any mods, removed the ones that were outdated, backed-up my files, updated, etc. etc. etc.
I even did all the steps suggested in the Game Help thread.
So this is my issue.

MY GAME WILL NOT LOAD. NO MATTER WHAT. If I try the launcher, it doesn't freeze but it closes like normal as if the game were about to load then nothing happens at all. I tried bypassing and using TS3W.exe. I tried removing origin, I tried removing all custom content and moving the DCBackup. I have literally done everything. I tried searching the internet for an answer, I couldn't even find anyone else having the same problem as me with any of the previous versions. All answers just say to bypass the launcher and it did not work.
I also tried re-installing, which also did not work.

Sorry is that was a lot, I would really appreciate some help. :c

Did not load at all? Did ts3w.exe show up in Task Manager? No error messages at all from Game_Help:TS3_Load_Issues^wiki? The Long loading times section has a link to Process Monitor in the "Package File Lag" article. You can use that ProcMon utility to see what ts3w.exe is doing while it runs.

Or crashing? Worked through each and every step of the Game_Help:Sims 3 Crashing Checklist^wiki?

Heyoooo.

Thanks for replying and all. To answer your questionss.
No, it did not load. Nothing came up in Task Manager, I even looked under processes for hidden task branches. No error messages. I will definitely use that next time, thanks. AND no crashing and I did all the steps.

NOW for the good news. As I was not wanting to wait for a reply yesterday ( I am impatient.) I decided to just uninstall both showtime and the basegame, remove all CC, Mods, DCCache, DCBackup, Saves, and all that jazz. Wait another two hours for the Origin. Re-installed, updated. IT WORKED. Vanilla...

So I just figured out something in one of my neighborhoods or old custom content was corrupted. I got most of it back in the game and it works fine now. So if anyone has this strange issue you are unfortunately going to have to uninstall the basegame. Fortunately, you don't have to uninstall ALL games like you used to have to do with The Sims 2. Or I did, at least.

Thank you again for responding, ellacharm3d. c:

I am having the same issue, Everything was working fine I bought the Showtime expansion and installed it after updating the game and Now whenever I go into live mode the game crashes.
I deleted my neighborhood after exporting the few houses and sims I didnt want to lose permanently and I followed all of the instructions on clearing cache's and the custom content but It still crashes regardless if i use a home I made or one that already existed in the neighborhood .

I am uninstalling the game and all the expansions now and will wipe all the folders and re download and install them again...

That's not the same problem, webgenius. If it's still happening once you've reinstalled, please make your own thread.