I have one of those that I bricked via a botched firmware upgrade, knocked it off my desk while it was writing. The error message yours is giving means the cart's firmware is out of date. If you can find an older version of the kernel (the software/files you put on the sd card) online that might work, otherwise it's possible to use ysmenu instead of the 'official' r4i-sdhc software. See: https://gbatemp.net/threads/ysmenu-for-r4-sdhc.187663/ That should at least let you use the cart again. Hope this helps a little.

 

its not broken or anything.

these carts come with expiring firmwares (meant to encourage users to keep updated)

go to your nintendo ds' system settings and turn back the date to last year. it should work again.

or update it with a new firmware, if they still release new firmware for it