Rom download for ben 10 and new penguin game problem

Hi
I have downloaded the rom for Ben 10 and the new penguin game for the ds. Put them on my DS and they just come up with black scren stating unable to find save fileplease restart ds??????
Is this anew problem with the latest games or am I missing something ?
Al older games work fine.
Any help appreciated
Jon

Read this and see if it answers your question: https://www.romulation.org/forum/index.php?topic=1462.0If it doesn't, we need a bit more info like what type of flashcart you're using.