My Sims Cant Go Up Or Down Stairs Sims 4 Delux. [ Edited ]

[StrifexHart]

So I recently got the sims 4 deluxe and the Go to work expansions package with it. The problem is my sims cant go up the stairs, I cant click on the stairs or anything. The only way I can get my characters to go up the stairs is if I follow someone up there. I have uninstalled and reinstalled the game to see if that would fix my problem. It didn't work, I also haven't downloaded any mods or anything like that. I honestly don't know what to do. I am playing on my PC not console. Any help would be appreciated. Thank you 

[PugLove888]

@StrifexHart, the stairs themselves are not clickable in the Sims 4.  But usually you get your Sim to go up the stairs by telling them to do something on the other floor.  
Does this just happen to the one Sim?  Does it happen on other lots?  if this is happening to all your Sims, you can try to see if it happens in other Save Games.