If there is not enough free space in the built-in flash memory, delete unnecessary files or export recorded files to a computer. Necessary free space may vary, depending on the bit rate or recording time.

If the maximum number of files that can be recorded is reached, delete unnecessary files or export the recorded files to a computer. For information on the maximum number of recordable files and folders, see the related topic.

If your Walkman is connected to a computer, disconnect it from the computer.

If the serial number of the file name has reached 999, create a new folder.