Grand Ball's Event doesn't work .

When I go to plan a Grand Ball in the sims 4, the tasks won't show up, and neither will the guest's. First I thought it was because I planned it days ahead, so I tried instead to use the waltzing dance floor and instantly start a ball, and yet when I tried that, it still didn't work. No one showed up, and no tasks appeared. 

Now I dont know what to do, is it the mods? or is it the game. I have downloaded the latest updated mods, and updated the game. The issue appeared before the latest update also, but then I just had to go to "manage worlds" and back to fix it. But now I have gone to "manage worlds" multiple times and it doesn't do anything, i've even tried to close the game. 

So if anyone knows how to fix this issue, please let me know. 

Sincerely, a dedicated sims player