Sims 3 Complete Collection - Null Pointer Exception and install not completing

Hi! I downloaded the G4TW repack of the Sims 3 Complete Collection yesterday but have been having issues with the installer.

Immediately after I click to run 'Setup' as an admin, I get a popup advising me "Runtime Error (at 141:21): Null Pointer Exception." If I click 'okay' it continues to the installer, but: a) I get the same popup everytime I click Next, and b) the screens I see are quite different than what I see in The Sims Architect's YouTube video.

eg. from the video: 



vs what I see:



If I continue on with the installation process, it does extract the files but after that just stops - with no message that installation has completed or anything. It doesn't create any Start Menu nor desktop shortcut, and if I run TS3W.exe (for the base game) I get the "Unable to start game Service initialization failed (0x039e8474)" error; if I try to run the launcher or just TS3EPXX.exe I get an error that the game is unable to start and I need to reinstall the base game.

I have had a version of TS3 installed before, but I've cleaned out my old My Documents > Electronic Arts > The Sims 3 folder and have checked the registry for TS3 entries (there were none). Any help greatly appreciated!

Welcome to the Forum,

I'll assume you are talking about that (newer) "all-in-one" .iso file? Did you mount the .iso file in a virtual drive, with a program such as PowerISO? 

If you have Windows 10, you can do it even more easily, by right-clicking on the .iso and then choosing "open with -> Windows Explorer". And from there navigate to the installer and run it. I suppose you could also try "extracting" the .iso contents while viewing them with the Windows Explorer...simply by copying the stuff and pasting it into some other folder. Normally though opening the .iso with the Explorer should do the trick.

As a last resort, you could try forcing a re-check. Usually when you right-click on a torrent in your torrent client, you have an option like "force re-check", which will check the hash of your downloaded file(s), and if necessary re-download any broken packages. 

Not sure what else could help at this point though, but feel free to keep us posted!

A friend of mine was having this same issue on his Windows 10 PC. 
To check, I downloaded the same all-in-one installer and tried it on my PC.
After mounting using file explorer, I opened the setup, and I got the correct setup like in that video you posted.
I looked into this and realized the PC my buddy was using was still on windows 10 1803. Mine was on 1809. After updating to 1809 his was fine. Try that

I'm having the exact same issue with a friend of mine. I downloaded the game and installed it all fine on my own PC, took the data in order to install the game on another PC to my external HDD, and it worked fine installing it on another PC (Laptop). Then i tried the same on another PC and it gave me that Runtime error. I hope someone can give some insight here. The PC it didn't work on was also outdated like Rankourai said, and I did update it to the latest Windows 10 build but it still gave me the same error.

Any Ideas would be greatly appreciated