installer - How to show pop message before majorupgrade -
how show pop message user wants upgrade new installer or not before major upgrade. i tried majorupgrade element, able downgrade custom actions not major upgrade. if using majorupgrade element wix_upgrade_detected property defined when upgrade performed. can define new dialog or pop-up in ui based on property. you'd need modify publish element want put ui so: <publish event='showmajorupgradedialog'>wix_upgrade_detected</publish>