I’ve downloaded a Sim/House/Household from the exchange but I can’t find it in CAS or in the library
There are many Sims out there that cannot be installed through the launcher. They will show as installed but next time you open the launcher, they are uninstalled again. I don’t know why some Sims show this behavior but it’s possible that CC has something to do with it.
When a Sim/House/Household is installed through the launcher, a file will be saved to the SavedSims folder (or the library folder in your user data directory. For some reason, this will not happen to those uninstallable files. They will not appear in your those folders.
Those Sims will also cause issues with SimPort. You won’t get them into your game, since they can’t be installed in the first place. You will see a message that the Sim has taken a wrong turn somewhere.
Convert those files into package files or get the corresponding file from your DCBackup folder. If the file is a house or household, you can then move the file to your library folder, if it’s a Sim, you need to set up a mods folder and put it in there.
After placing them in your town, you can re-export them and delete the files.
There are no solutions for the SimPort issue. Ask your friend to send another Sim.