R4 DS cannot read data please turn off console and re insert card

Ive had my card for a few months now and it been fine but yesterday I downloaded a load of new games and got rid of some older ones,
but with the exception of two none of them work and I just keep getting the same cannot read data message:
The ones that wont work are top trumps, imagine fashion, my sims, drawn to life, zelda, nancy drew&touch detective 2, but chibirobo and thrillville do.Im assuming there isnt actually anything wrong with the roms, but I dont understand why its doing it?If anyone else has had this or knows how to fix it please help,thank you

You need to download an updated firmware for your R4, I believe the current version is 1.11

literally just did that b4 I read you reply! lolIt worked, so thank you :)