i have ds simply i never had a problem until today i changed the arm7 with dslazy on a new game i popped it in the ds and i got a message "save data could not be found reinsert ds " card i tried a couple of new games got the same message on new games but the old games work fine any help is appreciated thx .
Some need to be patched differently, unfortunately it is getting harder to get everything to run as all support for that card has been finished. Look at gbatemp.net, they have a different operating system you can use and an R4 / Simply forum for this issue