I hate to admit this but I'm dummer than the dummies I guess. Have the game working on 3 desk tops and one LapTop but trying to install again on a new desk top with Windows 10 Pro and having problems. I know I have seen comments on some of the problems but it was so long ago I couldn't find anything going all the way back thru the Help Forum. Ok here it is, when I install an expansion pack, it comes up with wait, want to check if this is the latest or some such stuff, but I log off (shut down) and then come back and install the Patch before going to next expansion pack. Seems Ok and then every so often I try to play the game, and low and behold get an error message, You have uninstalled University, or Open for Business or Seasons. I either reinstall or decide to just forget it and keep going, but now every time I get to Free Time, I get an error message saying I've been prevented from downloading this App. Can't seem to get around it, same applies to Apartment Life, Mansion and Garden Stuff...
I went thru the registry Current User and Local Machine\Software\Wow6432Node and also Microsoft and can't find anything I didn't already install. Looked at a Help thing that talks about installing all the disc and then run Autorun on Base Game and install all at once but hope this isn't the only way, never did it before. I did have a problem with One Drive also but a technician fixed that for me. Machine has a 1 TB SSD partitioned as C and D drives, over 300 gigs free on each. Any help appreciated.

SOLVED ONE PROBLEM: The error message "An Administrator has blocked you from downloading this App, for more information contact the Administrator" Go to Reg edit, Local Machine, Software, Microsoft, Windows, Current Version, Policies, System, Enabled UA......delete the 1. Exit, reboot computer and wala.

Are you sure the patch actually worked? That error message may be telling you it's missing some files in the EP data installation. And that's what the patches did to me when I tried installing them (if I remember correctly, they crashed near the end before saying it was patched successfully, and when I checked the game data, the objects.package of the EP was replaced by an empty file).
You can check here, page 8 and later:
https://www.modthesims.info/showthread.php?p=4051458
Basically you would have to use that program (Grumpy Loader) to install all patches in the TSBin folder of both base game and every EP and SP before moving to installing the next EP/SP. Also for the patches you have to download.

Windows 10 isn't compatible with securom and safedisk and the game uses both, that's likely why you're having trouble installing them.

I was having the same problem,
An Admistrator has blocked you from downloading this App etc.....
I followed your advice and it worked Eureka!!!! \
Bless you!