Are any of your mods, including the Careers mod, or other package based content you may have working correctly? (do you have an NRaas > Careers mod menu on City Hall now as well as mod menus for any other NRaas script mods that provide them like Overwatch, MasterController, and StoryProgression?)
If so, Misty provides her mod downloads as .rar files. If you haven't already done so, you would need to use a third party tool such as WinRAR or 7-zip (I recommend
7-zip because it's Free and Open Sourced) to extract the package file inside and that's what gets placed into Mods/Packages. The rabbit hole rugs should show up where the other rugs are in Build/Buy.