Downloaded through Steam, cannot run.

As the title says, I've downloaded Sims 4 through Steam. My wife and I have the same computer, same download path, everything, and her's works fine. When I try to open mine it says that files may be missing or that my mods may be corrupted. I haven't had this game downloaded in forever and have never used mods when I did. I don't know how to make this work. It's downloaded onto the same SSD that I use for all my games. I have plenty of space on it. HELP PLEASE!