I got an NW-A25 recently and have been learning the ropes. I had an issue where when I put in a 512 Gb samsung microsd card (SDXC), it would cause the player to lag, and eventually crash. This is because the walkman firmware doesn't like it when the cover image is included in the directory, but not embedded in each individual music file. The fix is to make sure that every music file has the album cover image embedded in it, i think. Just wanted to make this post to add some visibility for troubleshooting! Hope this can help maybe Details: - formatted the sd card from the player (Home -> SD Card Settings -> Format SD Card -> Yes) - i also tried to check that the card was legit using f3 (https://fight-flash-fraud.readthedocs.io/en/latest/introduction.html) - (the actual fix) I embedded the cover images to the flac files I put onto the card. This eliminated lag/crash issues related to the SD for this case. --> i used a python script someone else supplied, and ran it on the SD card's directory since it destructively modified the flac files Sources: Thread that introduced this fix - https://www.reddit.com/r/walkman/comments/18ffbjk/script_to_embed_album_art_in_flac_files_for_the/ used this python script to embed in bulk - https://github.com/kitschmensch/embed-artwork