Please help with plugin I can't install

please help i can’t install extension plugins, what is wrong?
when i downloaded the rbz file from sketchucation and opened it, it states “no results found for this filtering”
i went to sketchup>window>extension manager and tried to install it and this happened

Using Install Extension in the Extension Manager is the correct way to install extensions you’ve downloaded to your computer. It looks like JHS Powerbar has installed just fine. It isn’t signed but as long as you don’t have loading restrictions set to prevent it, that’s not a problem.

remember that with some extensions, it is necessary to restart sketchup after install so they load properly.

It doesn’t mean it’s not been installed pr that it won’t work…
However, unless your Extension Manager’s Loading-Policy is set to ‘Unrestricted’ it won’t be loaded as SketchUp starts.
If you get an Extensions from a reputable source - like EWH, SketchUcation-PluginStore or directly from an established author’s web-site - then you should have nothing to worry about…
‘Signing’ extensions is a time consuming process, and for many authors of ‘free’ extensions there’s little incentive to do it frequently !