This is an issue caused by the UI Cheats mod. For future reference, on the day of an update you should not re-enable mods unless you know that they are compatible with the latest update. This should prevent problems like this in the future.
Product: The Sims 4
Platform:PC
Which language are you playing the game in? English
How often does the bug occur? Every time (100%)
What is your current game version number? 1.61.15.1020
What expansions, game packs, and stuff packs do you have installed? none
Steps: How can we find the bug ourselves? no idea
What happens when the bug occurs? i go into build mode and the ui doesnt show up, but i can still move stuff and place walls with the b shortcut.
What do you expect to see? the ui working fine
Have you installed any customization with the game, e.g. Custom Content or Mods? Yes
Did this issue appear after a specific patch or change you made to your system? Neutral/Not Sure
When I opened sims up today everything worked as usual ( i was making a family) once i made the family i tried to redesign the house i just moved into and the ui just didn't show up, i deleted the out of date ui mod and tried to reopen the game and i was greeted with the same problem, so i removed all the mods out of the folders and alas the problem occurred again, i even uninstalled sims but no use ? why is this.
