Stair Railing UI not Appearing

Please try the following to test in a new user folder:

1. Close your game and EA App.
2. Locate your "The Sims 4" folder [Documents > Electronic Arts > The Sims 4]. Make a backup of this folder and save it in a different, safe location. 
3. Repair your game.
4. Rename your "The Sims 4" folder to The Sims 4_OLD (or move it to your desktop... Do not delete it - you need it for reference). 
5. Now re-open your game and begin a fresh game save without adding in any of your old files. (No worries... The game will create a brand new replacement 'The Sims 4' folder.)
6. Now check in the new game save to see if this issue is still occurring. 
7. Save and close the game.

If the issue is not there in this new save you can then begin re-adding some of your old files, testing after each step to see if the issue is still gone. Copy (so you leave the original in your old folder) the following into the new "The Sims 4" in this order from your old folder:

1. Saves folder (contains your old game saves):
   While the game is closed, copy your "saves" folder from your old "The Sims 4" folder and paste it into the new "The Sims 4" folder. If prompted say yes to 'overwriting' the "saves" folder in the new "The Sims 4" folder. Now open your game, enter a new game save and see if the issue is still gone.  Close the game. 
2. Tray folder (contains your old library):
   While the game is closed, copy your "Tray" folder from your old "The Sims 4" folder and paste it into the new "The Sims 4" folder. If prompted say yes to 'overwriting' the "Tray" folder in the new "The Sims 4" folder. Now open your game, enter a new game save and see if the issue is still gone.  Close the game. 

Other files you may want to do the same with if they are important to you are Options.ini, Screenshots, Recorded Videos.