Hi try open that file from windows explorer, using the same path where the data connection is trying to open: Edit the 'section_7' data connection, copy the data connection path, close data connection without saving, paste data connection path the windows explorer and navigate to the other forders: Section_7 data files, and check that ther is the file.
Also check file permissions, the user loading the script, or the using starting the Qlik Sense services in case of a scheduled task, should have permissions to open the file
