Thanks for trying to help me. Sorry if I posted in the wrong place. I don't use Sketchucation very often.I downloaded the latest LibFredo6 and also Tools on Surface and everything is Ok But I want to get rid of this message because I get it each time I open Sketchup. Where should I post my message to get help.

@jjbrown said:

PLEASE HELP ! ! AM running OS 10.11.06 sketchup pro 2018 an trying to load libfredo6 an for some reason its not loading in extension warehouse ... ive even tried loading it into sk 2017 with no luck . just cant figure this out .....
Download the latest version from our PluginStore, https://sketchucation.com/pluginstore?pln=LibFredo6
The RBZ should then be found where you specified - usually your Downloads folder ?
Use the native Extension Manager > Install Extension, find the RBZ file and install it.
Remember that LibFredo does nothing much if installed on its own.
It is however required by most of Fredo's Extensions...

u can take a look here too http://www.youtube.com/watch?v=GBI_SXWoOjc