@diopter77 I checked for myself on an EA App install I rarely use, and one where I hadn't ever signed into the game either through the launcher or at the Main Menu, at least not with that user folder. Inside Downloads, I only had my downloaded items plus FSIViewCountTracking and nav.bin. When I signed in at the Main Menu, I saw a bunch of badge-related files, plus [my email].bin. I never saw an MSI.bin.
Interestingly, wl.bin wasn't present, and also isn't present in a different test user folder from August, where I also wouldn't have signed in. And the file wasn't created when I signed in either, but it did get created when I exited the game a minute later, or possibly when I opened the launcher immediately after that. And after I deleted the Downloads folder and opened the launcher again (without signing in), wl.bin showed up again, along with nav.bin but nothing else. So it appears that the game stores the record of my having signed in somewhere, or some related data, and recreates wl.bin thereafter.
This is kind of a moot point though, at least as far as your issue is concerned. This folder I used to test has very little launcher-installed content, but that content did load in-game. What I think here is that your launcher-installed content is no longer recognized for some other reason unrelated to the files in Downloads. To try to fix it, please remove the SigsCache folder inside the main Sims 3 folder.
If that doesn't help, please use Method by Mell in this article:
https://sims3.crinrict.com/en/2011/01/tutorial-how-to-get-rid-of-unwanted-custom-content.html
to test each of your .dbc and .ebc files in DCCache individually. (You can test one of each at a time; they don't affect each other.) The idea here is that the game stops reading all of the .dbc or .ebc files as soon as it encounters one that's corrupt. So it's possible some of the files may be intact, and the game would be able to use them if the unreadable files weren't getting in the way. If so, you wouldn't need to reinstall everything, just the items bundled into the corrupt files.
If all .dbc and .ebc files are corrupt, you'll need to delete them and reinstall your existing content through the launcher, unfortunately.
As for looking for bad/corrupt files, the mod should have picked that up. Some info on the MSI.Bin from 2016 nraas web page.Thought was a stuck aging up sims possible. Still does not explain the missing email, or wl.bin cause unknown. Great for you that your game is perfect for me not so much stop gaming middle of dec and open to a mess that was my own doing of not thinking the launcher for launching game non sign... not into the store... was not up to par. Do use the offline an shortcut not the app still need to use the app and select offiline an the choice of sims 3 or sims 4 in my case, click the shortcut on the desktop, starting from the desktop still goes to launcher with the no sign just guessing thats why an email address is in the download folder... You still have to go click an launch the game either way. Sure some will go from the file folder and click have not,might go a head see what happens. Even if I use the back up sims3 drive, still need to redo all the create a style/cas &build mode as well, thinks its a new game. Also notices that when your in the cas,click open the launcher it was missing the checks on the installed content part in an older save. Working on snip. New finding go to the loading screen click open launcher from the desktop. 2 launchers. This download file is toast! Will try an rename download file moving it out to desktop and launch again maybe some of it will be okay lol. New download file no email. Just nav.bin an wl.bin is back no email.
@diopter77 Again, I don't get the [email].bin file until I sign in at the Main Menu, and if I delete that file, it doesn't appear until I sign in again.
For the rest, please let me know what the problems are that you're trying to resolve. I don't think missing files in Downloads are relevant here, although it is of course possible; but I'd rather not spend time trying to figure out those files if the missing content can be reinstalled.
Hey move on to someone else... I will figure it out. kind of got that when the word moot was used, not practical importance; irrelevant.
You' all have a very wonderful day.
@diopter77 I'm not sure you understood what I was trying to say. As far as I can tell from this thread, and it's possible I may have missed something in your longer posts, you have one major symptom: content stored in the DCCache folder isn't loading in-game. (This covers patterns, Store content, etc., but not for example households, which are stored in Library.) You were also wondering whether the presence and absence of certain files in Downloads was related and/or pointed to a possible cause.
My response was that there was something weird about the generation of wl.bin, which I described, but that that was moot because it had no affect on my installed content. I also said that the same Downloads files don't always disappear for me but that this doesn't affect my installed content either. So while the question of which Downloads files appear when might be a curiosity, I suspect that it is entirely independent of your main problem, as I read it. So in my opinion, pursuing the angle of the Downloads files is a waste of time with respect to solving your issue.
If you want to poke at it further, fine. If you want my help in addressing the missing Store content, I'm here. But I thought the goal was to solve the issue, and I don't think pursuing the Downloads files question furthers that goal.
