The error "The file does not appear to be a text file" appears when I copy paste perl code from windows into course.config using the Webwork editor, opened out of File Manager.
My windows editor is nppp/np++ and I have it configured for UTF-8 with line endings \n (as needed by linux). UTF-8\n is what Linux uses, right?
Once I save and close the file with Webwork editor, I can never open it again with Webwork editor.
When I try to edit the file directly in a linux terminal, /opt/webwork/courses/course_name/course.config I have to change the permissions, edit, change them back.
-rw-r--r-- is 644.
sudo chmod 777 course.conf
edit the file
sudo chmod 644 course.conf
What a pain! but OK, I got what I wanted. Still, I cannot ever open the file again with the webwork editor out of File Manager. Why ???
View file does not work either, same message.
If I download the file to windows, it is fine, the changes I made in Linux are incorporated, the line terminator is \n, everything looks good.
PS. Using Webwork 12 in Ubuntu 16.04