When i load bt it fails with some errors

SQUASHFS error: sb_bread failed reading block hex
SQUASHFS error: Unable to read fragment cache block [hex]
SQUASHFS error: Unable to read page, block hex, size hex

first i thought maybe the dvd has a problem, i burnt it twice, same problem. Then i thought the writing speed maybe needs 16x. same problem. I tried it using USB and Virtual box and same problem.

Downloaded a new image KDE 32 and same thing.

But when i downloaded Gnome 32 everything was fine.

can the ISO image from KDE 32 be corrupted ?