Keil Microcontrollers

Hi, I downloaded an example application in Keil. When I rebuilt it for the first time, it gave an error because the code uses compiler version 5.06, but I have a newer version of Keil. I downloaded compiler version 5, but it still produced errors. I then switched back to compiler version 6 and tried to fix them, but the issues persist. I want to fix the errors, clean up the code, and get it ready to flash onto the chip.