Try the following steps:
- Format your SD with SDFormatter v4 (be sure to enable "Format Size Adjustment" to "ON" under "Options" )
- Use latest Diskwriter and format the SD so it can be used by Diskwriter
- After the format, select the latest template
- Write 2 games to it
(From the same region as your 3DS console!!!)
(So if your (N)3DS (XL) is from Europe, use Europe rom release, if it's Japanese, only Japanese roms will work, if its US, only use US rom releases) (I know you can use regionthree, but that's another chapter, first get your sky3ds working with same region roms as your (N)3DS (XL)
- When done, use the safely remove option under windows to remove your SD from the computer
- Put your (N)3DS (XL) on and put in your sky3ds, if nothing shows up, wait a few seconds (Wait till the blue flashing ends on the sky3ds) and remove the sky3ds, wait a few seconds and put it back in your 3DS
- If nothing shows up, push the select button and see if a blue led starts flashing, if, wazit for it to end, if not, well, i don't know
never got the problem, try in another 3ds i would say.