Thank you!
It finally works now, the funny part was that all I did was delete the "C:/Program Files (x86)/Steam/steamapps/common/7 Days To Die/7DaysToDie_Data/../Mods" and moved those files to "C:\Users\Mathias\AppData\Roaming/7DaysToDie/Mods"
So apparently the mod ("Custom Perks - Prestige Skills") wasn't actually downloaded which I already knew from the start