First I couldn't click on anything once I opened the child's simology panel, I couldn't scroll down on it which was the first thing I noticed was broken, then I couldn't open her inventory, switch to...
Ideas
Are you using any lot traits or lot challenges? I also just had this problem and I started testing things, removing my lot traits and challenges allowed me to unbrick the game!
I had the lot traits:
Homey, Convivial, and Natural Well
I had the lot challenges:
Off-The-Grid, Simple Living, Wild Foxes, and Wild Prairie Grass
Hope this helps! I was extremely frustrated when it first happened to me too :)
How do you remove the lot traits if you cannot load into the lot?
