sims 3 opens blank screen mac

@kawaiisizzie  You don't need to ditch your saves, but it's a good idea to put them aside for now.  Move your entire Sims 3 folder out of Documents\Electronic Arts and onto your desktop, and the game will create a new one the next time you open the launcher.  Don't add any files to it, at least not yet; just see whether the game works.  Let me know either way.

If you still get a white screen, please let me know whether you use a third-party antivirus, and if so, which one.  Please also attach your deviceconfig.log to a post; it's in Documents > Electronic Arts > The Sims 3.  (You'll need to manually open the folders; the file won't show up in a search.)  You can delete your user and computer names, about 25 lines down, but there's nothing else in that file that can identify you.

I removed the Sims 3 folder and it worked after pressing play on the launcher, however, the glitch has started again. I screen recorded it this time and I have sent you a private message with the video. I don't use any third-party antivirus programs so I'm not sure what could be causing this issue. Apologies that the deviceconfig.log isn't in its original format, it would let me get rid of my name or laptop name so I had to convert it to pages and then a pdf, let me know if there are any issues with previewing it. 

*Edit: I just realised I used the new folders deviceconfig.log file, I can also upload my old folders file if needed.

@kawaiisizzie  The video didn't attach to the PM, but I saw it in your uploaded videos, and... wow.  Could you try lowering the graphics settings to the minimum let me know whether that makes a difference?  Try it with Advanced Rendering on and off.

Please change the graphics settings at the Main Menu, then quit to desktop before loading a save; otherwise, you could see some strange graphics glitches, although not worse than what you're looking at now.  By the way, if you did change the settings while a save was loaded, or you loaded a save afterwards without quitting to desktop first, please delete options.ini from the Sims 3 user folder and start from scratch.

The thing is, your particular graphics chip seems to be struggling more than most with running Sims 3, at least in Big Sur.  There may be an issue with the driver for that chip, and since drivers are part of the operating system, there's not a lot you can do for a driver problem other than update the OS and hope it comes with a new driver.  As it happens, there's a new update available now: you're on 11.1 from the version number in your deviceconfig, and 11.2 was released last week.  So you could try updating and see whether it makes a difference.  If you do update, another clean folder would be in order as well, just to be thorough.

The deviceconfig is fine as is, and I'd prefer the newest one anyway.  You can also open it in TextEdit if you want to edit it, but as long as the info is intact, the format doesn't matter to me.

By the way, if you could upload the video to YouTube or a different filesharing site and link it, that would be helpful.  There's kind of a trick to getting videos to play properly on this site, so while it's doable, it's not as convenient for people who aren't used to it.  And I'd like to share this video with some EA people if possible.

I dragged all the graphics to the lowest they could go, deleted the options.ini and turned the advanced rendering off. It worked perfectly fine and I also tried with advanced rendering on which also worked like normal. I have created a youtube video (here), however it is unlisted, so let me know if you need it to be public instead. I am going to update my laptop overnight but the issue seems to be with the graphics, however, I have always played Sims 3 on this specific Macbook after the 64bit version came out, so I am unsure as to whats changed. 

@kawaiisizzie  The video works fine; thanks for uploading it.  I've already passed it along.  I'm not sure what happened either, unless you first played the 64-bit Sims 3 in Catalina and only later updated to Big Sur.  The newer OS probably has a new graphics driver, and there might be other relevant differences as well.

When you deleted options.ini, did you do so before or after you changed the graphics settings?  That file stores the settings, so removing it would reset everything to defaults.  I'm just curious whether the game worked fine with the default graphics profile or with everything on low settings.  It could be that options.ini itself was corrupted in some way, in which case deleting it would have fixed the issue.

I removed the options.ini before I changed all the settings to the lowest. I also updated my laptop to the latest update (big sur 11.2) and I tried to load up my saves with my original Sims 3 folder and I got the white loading screen again. I hope I don't have to start from scratch or play without custom content. What should I do now?

@kawaiisizzie  Try loading the game in a clean user folder.  This doesn't mean deleting your saves and custom content, just setting them aside for the moment.  Move your entire Sims 3 folder out of Documents > Electronic Arts and onto your desktop, and the game will create a new one with no content the next time you open the launcher.  Don't add anything to it yet; just see whether you can start a new save.

If the game has the same graphics glitches as before, change the settings again.  If you get another blank screen, make sure iCloud isn't trying to automatically sync the contents of Documents: you can disable iCloud or just stop the auto syncing function.  This guide is for another issue, but the relevant settings are the same.

https://bluebellflora.com/2017/02/06/sims-3-and-sims-4-not-loading-save-games/

If that doesn't help either, try playing while your computer is completely offline.  You can sign into Origin and put it in offline mode, then disable wifi before opening the launcher.

I played a day and a bit in game to see how it would run and it was fine with wifi turned off. The only issue I had with a the new Sims 3 folder was when I loaded and exited the game, a glitches screen appeared, but it didn't cause any other issues. 

@kawaiisizzie  I can't see your screenshot because this site's virus scanner is on the fritz (again...), but if the game is otherwise working normally, you may not need to worry about it.  I'll take a look at the screenshot when it's showing properly, unless you want mte to look now, in which case, embed it within your post instead.  (There's a button for that along with the other formatting buttons.)

When the game works only with no internet connection, that usually means either iCloud is trying to upload the contents of Documents as the game is trying to load, or that an antivirus is blocking some connection the game makes to EA servers.  The latter has traditionally only been an issue when a third-party antivirus program is installed, but it's possible that Big Sur's security settings are more stringent.  Anyway, the place to start is with iCloud, and if that's not the problem, let me know whether you use a separate antivirus.

As I mentioned earlier, I do not have an antivirus program. I started thinking and I moved all my saves and custom content (all other files that were needed) to the new Sims 3 folder. I made a sim and played nearly a whole sim day and had no issues other than some custom content not showing up in game and custom content not showing up on my sim when I am far away (I think that has to do with the settings). Regardless, the issue of the glitch is fixed and I think it has something to do with the Sims 3 folder itself because it was showing the blank screen I had to begin with when I tried to open the original Sims 3 folder.