Issue with certain EP installation and "unknown error" problem.

Hi guys! First off, thank you so much for all the time and effort you all put in to making these games available for us.

I have downloaded the Base Game and every EP from G4TW, and have used the newest Installation Guide for Mac (the 20-05-2013 version) to convert the rar files to dmgs. However, I noticed that when certain EPs were installed (Ambitions, World Adventures and Late Night, I think), they don't appear in my applications folder like the others do. However, if I attempt to re-install them, I get a message that tells me that they are already installed in that directory. I uninstalled them all, and then installed them all in a specific folder within my Applications folder to see if that changed anything, but it didn't.
Also, I have also noticed that, if I attempt to open the game launcher once one of these EPs has been "invisibly installed", I get the "an unknown error has occurred" message, and the launcher doesn't even open. However, if I have only say, University Life or one of the others installed, this doesn't happen. I tried the fix listed on the Mac Fixes page for this issue (the one about deleting The Sims 3 Preferences and com.transgaming files and all that), which didn't seem to make a difference. However, (and I'm not sure if this is relevant or not) I did realise that, when attempting to install those 3 EPs (Amb, WA, LN) for the second time, the serial codes were remembered by my laptop and I didn't have to input them, which didn't happen with the others... And after I used the preference fix, the serial codes were not remembered, but the EPs still did not appear after installation.
I previously had the base game and Ambitions installed on this laptop (from actual CDs which have since vanished!) but they were uninstalled before I started any of this (again, dunno if this is relevant, but it might help!).
Sorry for this extensively long post, but I really wanted to give all of the info I could! I've been pulling my hair out about this for days! D:

Hello there,

Accidentally closed this topic, sorry!
I've unlocked it again.

Hello,

Sorry for replying late.
Just to clear some things for myself I'll ask some questions.
How did you install the games? I mean did you install the base game and Late Night and checked if they work or not? Then apply the others all you just added all one by one?
I suggest you to take things slow and reinstall everything. First install the base game, and update your game manually using this. And add Seasons, check if it works and let me know the result.

i'm not sure if it works but uninstall them all, clean your cache and every thing using some mac cleaner and reinstall them, I had the same problem and this solution worked for me  some times it just has installed badly, cleaning logs and caches might work