Please edit your post and surround the error listing with lines containing triple backticks. That prevents the forum from formatting the text and dropping the actual error message .
Thank you @sdmitch. I was with a similar problem and this code solved it.
This is not related to your problem @nnijmeijer but take this situation for upgrade some links that don’t work on Reference Browser, like:
Trimble API Reference: http://ruby.sketchup.com/ → line 194 from the file as_rubyeditor/ui.html
Trimble - Geometry Tutorial: link is missing → line 195 from the file as_rubyeditor/ui.html
SketchUp API Cheatsheet (PDF): link is missing → line 196 from the file as_rubyeditor/ui.html