I wrote this script to
Perhaps what is in it and is not correct.
But Ruby is well aware of it, let's
string = File.join (File.dirname (FILE), "Моя папка"))
string = encode_to_cp1251 (string)
Dir.mkdir (string) -> works fine
And as Sketchup 5 works great
A Sketchup 6 7 8 only read but can not green triangle icon
Encodes from cp1251 to utf-8
And a coding of utf-8 cp1251 (Cyrillic)
In SketchUp 5 everything works fine
encode_utf-8_cp1251