During the installation of a SeeYou upgrade the installation fails with the description 'MoveFile failed Code 5. Access denied.'. Sometimes also 'An error occurred while trying to rename a file in the destination directory’.
This happens if you are running a new installation file on your PC while SeeYou is still running in the background.
Close SeeYou before attempting to upgrade.
If it appears that SeeYou is not running but you still get this error reboot your computer then install the upgrade again.