EDGE DS 0kb .sav file

hey guys
i just downloaded some new roms
and i put it on my edge ds
and when i play it,it always freeze from the loading{all of my ds games}
and i realize that everytime i create a .sav file it is always 0kb
what is happening?ps:my sd card is not full

Upgrade your firmware. It's probably outdated and fails creating the save file.Go to www.linfoxdomain.com/nintendo/ds