That's what I was afraid of. Coincidentally, that happened when I turned my notebook on, and the OneDrive started to backup (previously it asked to and I said yes). The original folders have a error to synchronize with it, so after Felexsu's answer I looked it up on my Explorer and all my Sims 2, 3 and 4 were "duplicated" yet empty, like if it was the first time playing them.
Even tho were duplicated, Sims 4 and 3 were empty in the new one, and in this case I didn't lose my CC and saves. But I lost everything in my Sims 2 folders.
The only way to prevent this is turning OneDrive off, right? Because to make it the cherry on top, my OD keeps warning me about errors that it couldn't sync - .exe files only and I can't even delete the notifications and inside the Explorer there is a error icon very annoying.
And yes, it was everything you said. OD - Personal and just Docs. That was so frustrating. And then the EA App gave me trouble again, fixed, yet was another headache.