""An Unknown Error Occured"

I hope this is the right place to put questions, I'm so used to other types of forums  :newfag: 

Um... so... I'm confused as to where we're supposed to download the expansion packs? It gave a link for the base game, and I downloaded Stuffit and everything, but I'm not sure what I'm doing in steps 2 and 3. Can I just download the expansion packs from any old place?

Sure

Well. 
First : Welcome here
Second : Welcome on Mac

So, you'll need to Right-Click on the app -> The Sims 3 ( apps are actually folders with an extension that you can't see : .app - so all of your apps are : Name.app )
You'll see something that says : Show Content Package
Click on it.
A new windows savagely appear ! No fear, this is your app
Navigate to : Contents>Resources>transgaming>c_drive>Program Files>Electronic Arts>The Sims 3>Game>Bin


I'd recommend you do a backup of the files you gonna replace, you'll need them if you change your mind and install more EP or SP later

I restarted installation with the Mac guide, and after it finished updating and patching, it said "Unknown Error Occured" and now it won't open up at all! I've been trying to do this for 5 days and this type of thing keeps happening! 

I think I should edit this for my new problem now...

Ok …
Did you delete all files related to sims in your Library and Cache files ?
You might want to go in Disk Utility and repair your permissions.

I got the Sims to come up, but I don't know how//where to install the expansion packs. Sorry, I'm all over the place! Like I said, I took everything off and re-installed it, it came up with the error, and so I deleted the Sims app and then just clicked on the zippy file thingy again {don't remember what it's called, but you click on it and the Sims 3 app comes out of it} and put it in my applications folder and then it came up already updated and stuff...

Hahaha ! No problem. This time I'm the lost one.
Is the game working ?

To install the expansions :
if you install those by G4TW - just follow the same guide. You'll still need to mount the .rar to make it a .dmg ( stands for disk image ) and install all expansions.

It works just like anything else : you double-click the icon of the expansion that is inside your dmg and follow the wizard ( we just don't call it a wizard :p )

I haven't tried playing it yet because I don't want to screw anything up when I try to install the expansion packs.

So do I download the packs from this website? And if so, where do I go?

You will need, before installing any EP or SP, to update your game to the latest version 1.67 - it is a big update but you'll need it anyway. There is two links on this page to download it : https://games4theworld.forumotion.com/t3597-can-t-update-the-sims-3-to-v167-fix-manual-patch
Make your choice

You'll need to download from a torrent this time. I'll advice Transmission as a torrent app for Mac. Works fine and isn't in the way. ( https://www.transmissionbt.com )

On this page : http://www.games4theworld.org/downloads.html
You'll find everything. All EP and SP.

Since they are in .rar format, you'll need to follow the Part 2 of the Mac Guide ( here : http://www.games4theworlddownloads.org/Downloads/Guides/Sims_3_Mac_Guide.pdf )

Okay... and I think I updated it already. Like I said, when I removed it and re-opened it, it said it was updated.

It should be written on the left down corner, if you ever wonder what version you are up to

Keep the update file anyway, you'll need it when you'll have install every EP/SP you wanted, just to keep all files up to date again.

It says version 1.2.7.1

Another question... do I need to use Stuffit to download the expanion packs themselves or just extract them? I have "RAR Extractor Free" I downloaded from the App Store I have been using for awhile, maybe that's my problem?

According to the guide you'll need it. So you better use it, in fact, Stuffit is really a great app. Plus it opens more than just rar and zip files

Your game doesn't look at the good version to me. Just to be sure, update it again. Won't break it

I can't update it again... it says it's up to date and I can't click anywhere else to get an update.

Manually update it.
Download the update from the links I gave you previously

Ah, okay, thanks! And afterward I can start with the EPs?

Yes
After that you can start with the EPs

Remember to follow the steps to mount the EP.
Update again ( with the manual patch ) when you'll have install all that you wanted
And finally crack

Okay so I updated with the MEGA one, is that okay?

And to mount them... does that mean put them on a flash drive? They don't fit on flash drives-I only have a few with small capacities- and I tried using my sister's external hard drive which has a terrabyte on it, and my computer wouldn't let me put anything on it. Should I go out and buy a flash drive with more space to fit them on?

It is perfectly fine with the MEGA one.

To mount it you shouldn't need a separate drive. Mounting means emulating a CD on your actual drive. If there is a step you don't understand in the guide about mounting just let me know

I don't really get mounting at all! >.<

Hahah

You'll need :
- Stuffit
- An expension in rar file ( which you'll get from the torrent )

Ok. Once you have the EP. ( those info are in the guide  )
- Double click the rar file. Stuffit will expend it for you.
- Check the size of your new folder, make note of it.
- Fire up Disk Utility ( that is in your Utility folder that is in your Application folder )
- Click on "New Image"
It will ask you for a name ( Save As & Name ) : have fun, put whatever you want
As for the Where : again, choose put just to keep it simple, let's put in on your Desktop
Size : the size of your folder+0.1 GB
Don't touch the Encryption, Format and Image Format
Partitions : CD/DVD
- Check your desktop -> there is a .dmg ! Sure it is empty but still !
- Open the folder Stuffit did and select all ( cmd+a on your keyboard ) files and folder
- Drag them to your .dmg

Tada ! You've just did your first Image Disk. That means that your mac sees a CD and it will read whatever is in it like it should be.

Double-click your dmg. Héhé ! 
You should see an installer : The Sims 3 Whatever-ep Installer -> double click it like your life depend on it ! ( just joking :p )

There, you should have an installer popping-up.
You'll find serials in the #Installation Guide.txt included in the .dmg
When ask where to install, just choose the same folder as your base game.
Keep going on until the EP is install.

You can unmount the .dmg after the installating. Just trash it.

Re-do for each EP

Could you please explain? Hahah

Explain what exactly ?

Oh, sorry, I didn't see your response!    Thanks a ton, I'll try following those steps and the guide and come back if it doesn't work. Thanks so much for your help!!!