CL-NX Print quality issue (vertical white line or partially not printed)

<The causes frequently observed>
(1) Improper loading of labels
(2) Dirt such as adhesive or piece of label on the label route

< Measure >
(1) Please refer to the below link and reload the labels and the ribbon accordingly.
(1) Please reload the media (labels and ribbon).

(2) Please clean the thermal head and platen roller.