UI & MC mods

I'm new here 🤚I've been having issues with my game where things are just blank. For example I made a new sim but in live mode when I tried to click on her needs, the window pops up but its just a blank screen. 

I'm not super in depth with computers and programing but I watched a youtube video on how to install the mods. Everything was well and good until about last week. 

Help?