The source media you are installing from is damaged. Try installing from a different copy of the source media or contact the manufacturer fro a replacement.😡
I wiped the disc... now i'm getting this message. The installer could not install some files in "volumes/macintosh HD". Contact the software manfacturer for assistance.
Apple sent me a replacement disc and now this is the error i'm getting. "the Installer could not validate the contents of the "Essentials' package. Contact the software manufacturer for assistance."
If you were having problems writing to this disk last time and it's occurring again it might be the hard drive itself since this Leopard installer media is completing its integrity check successfully.
I had the same problem. Leopard installed fine on my two other computers but when it came to a mac mini it gave me the same error. I had to do an erase and install and it worked fine. If you are doing the upgrade option, that is where the problem is.