PLEASE NEED HELP TRYING TO PUT GAMES IN MY R4

Every time I try to put a game in I get an error code, "Invalid MS-DOS Function" has this happened to anyone else, and if so, is there a way to fix this? It's very frustrating, and I can't seem to find an answer anywhere I look. Please and thank you.

format your sd card and rest from start
(buy an acekard 2i)

That worked. Thanks alot!

np