### UNDO

Undo changes made by QAD.

QAD commands that create, modify or erase objects affect all visible and editable layers, and not only the current layer as QGIS does. That's why QAD uses its undo/redo system that operates on all layers involved into QAD commands

If the user will run the Undo/Redo command of QGIS, QAD will lose alignment with the history of the changes made by its commands and then the undo/redo stack will be cleared.