Plugins in 2016

Where do I copy plugins in SU2016, there is no plugin file under sketchup

instal fresh copies [that have the .rbz file extension] using Preferences >> Extensions >> Instal Extension…


There is a Plugins folder for SketchUp but it was moved a few versions back into User/App Data/Roaming/SketchUp/… It’s a hidden folder so you would need to make it visible first. As John said, though, you should install fresh copies of the plugins/extensions instead of copying the old ones.

See this Help article and the many links within it…
Installing Ruby Plugins (Extensions) — SketchUp Help