@fredo6 said:

Sorry, you have to put it in the bezierspline subfolder in the Sketchup Plugin directory.

Thanks, that did the trick.

@fredo6 said:

If you put the PDF file in the Plugins directory, then it will be available from the menu.

I placed Quickcard BezierSpline - English - v1.2.pdf and Tutorial BezierSpline - English - v1.2.pdf in C:\Users<username>\AppData\Roaming\SketchUp\SketchUp 2017\SketchUp\Plugins, as you said, but still nothing happens when I click on Draw > BezierSpline curves > Documentation... .

BTW, your link to Scott Onstott's tutorial leads to a non-existent page.

I just downloaded BezierSpline_v2.1a.rbz from the Plugin Store and then installed it from SU's extension manager (I have SU Make 2017 on a PC, by the way). It seems to have installed properly, but when I click on Documentation in the menu, nothing happens. So I downloaded the Quickcard and Tutorial PDFs, as well, but I don't know how to make them available from the menu (assuming they should be, of course). Are these PDFs the only documentation available, or is something missing?