Unable to install Extension

I went to install the extension to SketchUp so that I could export .skp files to .stl files for 3D printing.  I selected the extension under Preferences>Extensions>Install Extension but it gave me the message "SketchUp was unable to install the Extension you have chosen for some unknown reason.  Consult your Extention's documentation for additional help."  Does anyone know what the problem may be, and can you please help?


Is it the RBZ version of the plugin?

To install the plugin that way you need to use the RBZ version - is that the one you used?

If that method fails you can just copy the RB file into your Sketchup extensions directory.