Arturia KeyStep Pro Keyboard with Advanced Sequencer and Arpeggiator - Manual (Page 130)

6.3.6. Undo
Of course, there's always the risk that you erase something unintentionally. Fortunately, the
KeyStep Pro has an undo function. It can't save you all the time, but when available, usually
after a critical erase, the Exit button blinks.
To undo a Paste or Erase operation, hold down 'Shift' and press Exit/Undo.
Undo is also useful to undo the last recording you made. Undo will restore the KeyStep Pro
to the state it was in before recording started.

♪ : Undo will only undo Paste and Erase operations; it will not undo randomizing notes in a Pattern or
any of the other Shift functions.
Another way to undo changes is to restore a pattern to its original state by holding 'Shift'
and pressing Save. this will undo all the xchanges you made since loading the project.
124 Arturia - User Manual Keystep Pro - What is a Project?