Backup your µSD to a Backup folder on your PC BEFORE upgrading to a new Kernel

Format your µSD with the Panasonic SD Formatter 3.1
Use these options :
FORMAT TYPE - FULL (OverWrite)
FORMAT SIZE ADJUSTMENT - ON

PRIMARY Kernel :
Extract the files from the DSONEi SDHC YSMenu folder and copy to root of your µSD :

Games folder
TTMenu folder
SCFW.SC
TTMenu.dat


DUAL BOOTING :
Download the latest EOS Kernel and extract to root of your µSD.
Extract the files from the DSONEi SDHC YSMenu folder and copy to root of your µSD :

Games folder
TTMenu folder
MSFORSC.nds
TTMenu.dat

Boot EOS then load MSFORSC.nds for YSMenu.