gmb24984 For the Store worlds (RH, MV, HS, BB), please see the first post of this master thread:
[Current Issue] Sims 3 Store world can't register/install | EA Forums - 11143823
For the stuff packs, do they show as owned in the EA App, under Sims 3 > Manage > Manage add-ons? If so, and you can install them from there, please do so. If they then don't show in the Sims 3 launcher, please let me know.
If the packs don't show as owned in the EA App, please check Account Settings > Order History on ea.com. If they're not there either, you may have signed into the wrong account, which has been very common for players switching from Origin to the EA App, and even after that.