This error usually means that the install files are corrupt or incomplete.
If the files are obtained from an FTP link, redownload or request another link.
If Unity Pro is being installed from a DVD,verify that the DVD is sound by installing on another PC.
If the files are obtained from an FTP link, redownload or request another link.
If Unity Pro is being installed from a DVD,verify that the DVD is sound by installing on another PC.