If the remaining battery power is low or insufficient, charge the battery. If your Walkman still does not operate after charging the battery, press the RESET button with a pen or a paper clip, etc. to reset your Walkman.

The data hierarchy levels of the content transferred by drag-and-drop may not be correct. Place them in the appropriate folder and hierarchy.

Transferred files are not in a playable format. See “Supported formats” for details on playable formats.

Content that is not recorded in playable formats is not recognized by your Walkman and will not be displayed in the lists.

Formatting your Walkman failed to complete, or you formatted the Walkman on the computer. Retry formatting the built-in flash memory of your Walkman.

The transferred content may be damaged. Delete the unplayable content from your Walkman and retransfer it, or delete the content from your computer and reimport it. When you import content, make sure that no other tasks are running on your computer until importing is completed. Otherwise, the content may be damaged.

If you change the file names or location of the content such as music that was transferred from your computer to your Walkman, the content may not be recognized by the Walkman. Return it to the correct name and location.

If you have initialized (formatted) the built-in flash memory of your Walkman using Windows Explorer, initialize (format) it again on the Walkman.

The USB connection to the computer may have been disconnected while transferring content. Transfer usable files back to your computer and initialize (format) the built-in flash memory on your Walkman.