I went to Window Manager Settings and on the Keyboard tab changed the Show Desktop key binding to win+d and it worked fine but as soon as I log out of Xfce and log back in this gets reverted back to ctrl+alt+d (default setting) even though the settings window is showing my custom shortcut of Super+d
Sounds like "deja vu" bug #4875, #5102, and also maybe related to #5055 Do you have set a different keyboard layout from the default?
Can you check if the migration script is started? If so, can you disable it (it should not run more than once).
Mark as invalid, no response from original reporter.