in sims it wont let me downlode any packs

I have downloaded the Sims 3 game but it wont let me install any expansion packs. 😕mileyfrustrated: i love you Sims and i hope u can help me! you are my #1 fan! :heart:

                                                                      ~from loved simmer

                                                                    ~thanks for putting your time and effort in reading this message

                                                                   ~ one request, can you please put toddlers in sims 4??? i miss them so much D: