When you run Pokemon Diamond/Pearl on NO$GBA for the first time, it says " The data could not be read, Please reinsert cartaridge." This has happened to me but later I found out how to solve the problem. First, start the NO$GBA emulator, go to the " Options " menu, and click on the " Emulation " panel. Next, go to the part that says " Emulation Speed, LCD refresh " and set it to " 16.78MHz Realtime, Auto ". Then, go to the part that says " NDS Cartridge Backup Media " and set it to FLASH 512K Bytes. When you're finished doing that, press OK and on the Options menu, click " Save Options ". Reset the emulator and the Pokemon Diamond/Pearl rom should work.