Allocate more memory in the Expand to RAM setting in the Preferences window than the file size to be played (default size: 500 MB).
If the problem still persists, select Normal.
NOTE: Selecting the Expand to RAM mode plays back music after storing music files in the active memory of your computer. By canceling file access during playback, the CPU load can be reduced, and you can play back music files with stable quality. Select this method when you want to play back music in higher audio quality.