I've heard about problems people have installing Store content, but mine are different. I have problems installing CC that come as sim3packs! And these problems have nothing to do with the launcher.

Most sim3packs install without a problem. But there are some that won't install and I have no idea why.

Description of the issue with most recent examples provided:

1) crashing during installation
http://modthesims.info/download.php?t=361106

This lot and other lots by this author (and many other lots by various creators) crash during installation. But it's not the launcher that crashes, it's the game. Basically, I click on this file, it prompts the launcher to load up and it does, then it prompts the game to load and it does... And that's when it crashes, a little short while after it loads up the game. No errors, TS3 just freezes forever (and meanwhile the launcher works fine). In task manager I can see that TS3 program stopped working when it reached 400mb in memory, every time. But I've installed larger lots before without an issue, so it makes no sense. It's not like my PC is out of memory!

2) no installation process at all
http://modthesims.info/download.php?t=497927

This is the weirest glitch I've seen. No installation starts at all. I click on a sims3pack and nothing happens. The launcher won't even start up, nothing happens at all. Maybe such sims3packs are just corrupt?


...

Basically, what's going on and what is causing it? The 'no installation' glitch is rare, but I'd really be grateful if someone told me how to solve the 'crash-during-installation' glitch. It happens to me so frequently it's like a curse. And no reintallation attempts ever work.

Re 1) The lot looks fine in both Custard and S3PE. But it is rather old. Maybe it does something that is not allowed anymore under later patch levels? IDK

Re 2) This lot contains a piece of CC. That may be broken. The lot itself is also corrupt and has an invalid UNKN resource, but as that particular thing has so far never prevented a lot from being installed, I'm not sure whether this is the cause of your problem.

Experimental solution:
Do this in a clean user folder, not in your regular game!!!

Extract both lots with Delphy's MultiInstaller
Lot 1 will give you one file that is also named accordingly
Lot 2 will give you two files with the ususal 0x0garblgarbl file names; the bigger one is the lot, the small one is the CC
Place the lot files in the Library folder and the CC into Mods/Packages. If your fresh user folder contains neither of these folders yet, make them first.
Start the test game and report back.

Both lots show up just fine in the game this way!

Thanks. Hmm so is this how I deal with lots that won't install: extact them into packages?

What about the second lot, you said it was corrupt... Is it safe to use it?

Yes and no. If the launcher refuses to install a lot because of some problems with the lot, it's perhaps better to not install it at all as you might carry something into your game that can cause problems later. If the Launcher refuses to install because of being the Launcher, then this is a way to circumvent that.
In general it is always better to install lots as package files after extracting it from the sims3pack and checking the sims3pack with Custard first and the extracted lot with S3PE. If you know how to identify problematic lots with both programs, then, yes, this is the best method.

Sort of. The corruption affects one of the resources and contains a broken piece of custom content that is not even on the lot. It's a CAS item, an accessory in fact and doesn't affect your game or anything else. Usually.
It would, however, be best to place the lot in your test game and save the placed lot to the Library bin again and then use that second one for your proper games. This procedure should clean the lot of the broken file.

ETA: Also tagging @attuned, because she is currently preparing a post with regard to this.

When I tried to move the files to the library from the 'clean' Sims 3 folder to my own, the game started crashing on startup. So I did what you told me, I saved the lot with broken CC in the clean game and copied its new file over instead of the old one. The game loaded.

Well, I'm not sure that the file was the problem, since just in case I deleted all caches, too...