You need to install plugins / extensions the correct way and stop copying / pasting it into a SketchUp sub-directory.
The correct way to install is to use the Extension Manager, go to Window > Extension Manager : Install Extension and navigate to where you had saved the RBZ file.
You'll probably need to fix your current install as well. An uninstall should do, make sure all the relevant files / directories have been deleted as well. Then start fresh using the correct method. When installing SketchUp, make sure to run/install "as administrator".