faresme , there are many v3.5.37 firmwares in the downloads section.
If your player is not detected by the MP3 Utilities Upgrade Tool, then you will need to perform the dead player recover guide.
http://www.mympxplayer.org/dead-play...ide-vt567.html
But if it is detected, then you need to try all the firmwares for your version.
There is no way of telling which works with your player, it's all a matter of luck.