In the folder that opens, look for a directory named plugins . If it doesn't exist, create one.
Click the button at the bottom of the window. Place the Plugin: Download File SurfaceSPREAD_v2.0.4_R23_WinOnly_...
Copy your extracted SurfaceSPREAD folder into this plugins directory. In the folder that opens, look for a directory named plugins
Once re-opened, you can access the tool within the C4D interface: Free C4D Plugins: Spline Guide In the folder that opens
Cinema 4D R23 requires plugins to be placed in specific directories to load correctly upon startup. Launch Cinema 4D. Navigate to Edit > Preferences (or press Ctrl+E ).