`su-wrapper-not-su-to-root`

The command in a menu item or in a Desktop file uses a su wrapper other than su-to-root.

On Debian systems, please use su-to-root -X. That will pick the best wrapper depending on which software is installed and which desktop environment is being used.

Using su-to-root is especially important for Live CD systems. They need to use sudo rather than su. The su-to-root command can be configured to invoke only sudo.