Usually these types of errors with the cdrom are caused by corruption of the installation media. Could you try redownloading the ISO and/or trying another usb key?
In the event it's still an issue, could you provide the contents of /var/log/installer please?
Usually these types of errors with the cdrom are caused by corruption of the installation media. Could you try redownloading the ISO and/or trying another usb key?
In the event it's still an issue, could you provide the contents of /var/log/installer please?