I think this error occurs because Mozilla Firefox is set as the default Web Browser in the Default Applications settings dialog. Since Firefox is not installed in the Minimal ISO, perhaps this should be set to "No application selected" as is the default Mail Reader. Since xfce4-settings is told that Firefox is the default browser, this is likely why users get an Input/Output error when selecting the Web Browser and Help shortcuts in the Whisker Menu.
I think this error occurs because Mozilla Firefox is set as the default Web Browser in the Default Applications settings dialog. Since Firefox is not installed in the Minimal ISO, perhaps this should be set to "No application selected" as is the default Mail Reader. Since xfce4-settings is told that Firefox is the default browser, this is likely why users get an Input/Output error when selecting the Web Browser and Help shortcuts in the Whisker Menu.