How can I successfully move my sims 4 game to my hard drive?

Hi! So I've been playing the Sims 4 for the past 3 years. I've went from mac to windows in that period of time so I've seen how the game plays on both systems. I was told windows/PC is a better option for game play. I recently came across the problem of running out of space so like many before me I went out and bought a 1tb SSD external hard drive because I've heard HDD is buggy (I've done A LOT of research). Moving on... I watched/mimicked a couple videos on You Tube and I came across a problem. I was able to successfully move origin and Sims 4 to the external hard drive. I understand I cant move my electronic arts folder from documents because it wont be read/found otherwise but when I open my game to play I get a pop up that says due to how many packs I have, the game wont run properly.

I have mods and cc but I didn't put them in my folder yet because I wanted to see how the game would run on the external hard drive without them just in case it doesn't run properly. I even tried to see how my game would run WITH my mods and the game wont even open. is there a way this can be fixed?