@nzbt Does the install path for SketchUp 2017 include non-English unicode characters within it? Are you able to use the shipped extensions that come with 2017 in 2016? To do this you can launch 2017, copy the shipped extensions and place them within the correct 2016 plugin path.
Lastly, feel free to send me an email with these 2017 Shipped Extensions and I will check them out on my side.
Thanks
Jon
jon@sketchup.com