Question When changing presets the Icon will sometimes show the following message "unused engine" and does not load the preset. Why Answer This is due to a mismatch between the Frame/DSP versions and the icon version (quite frequent with Icon version 5.xx). Make sure that your Icon software is up to date in all cases: 
  • 7.5 for the old Icon hardware
  • Latest for the Icon hardware mkII and for the Icon Editor.