I don't really know what has happened here. I see that it's not the latest version of the behaviour but I don't know why it's disabled. You could try upgrading it to the latest version but I suspect that won't help. Does the Moodle notifications page suggest anything?
Has this problem occurred with a fresh install of CodeRunner or did you used to have a working version which has now stopped working? If it used to work, what happened just before it stopped working?
If no-one here has any suggestions you might have to try a more general Moodle forum. This doesn't look like it's CodeRunner specific.
Richard