What does it mean by "must restart to installation"?

I restarted my computer a multitude of times, it has been over 2 months since I have posted this problem on reddit, it got taken down because of "to many other people have posted about help".  On the sims4, to be specific. I am autistic and am crying of my frustration. Please respond ASAP.

-Tessaswing

12/25/2023