Bad customer relation
It's a big shame that Soundcraft is not able to provide their customers, ever after about one year waiting, with an update to the offline editor that is compatible with the "latest" version of the firmware for the Si Impact. Caused by this fact you must decide update your desk or use the off-line editor, because after the firmware update you are no longer able to use the offline-editor.
And much more, Soundcraft does not even answer emails about that topic. I call that very bad customer relation.