the message you got might have something to do with needing admin rights to edit. i edited on windows machine and had no issue but perhaps on linux you need to edit while root. i do not know it just when you mention "no access" to a file that can mean opening editor via "sudo" maybe?
@György-Farkas , i just noticed this thread for first time and will download and refer to it while focused on the arduino dock. thank you for the effort in making the documents and sharing your work. i appreciate that.