Scenario is that we need to do some migration of files during installation and possibly show message box if some error occurs.
Issue is that we should do migration during system modification so we set custom action as deferred, and so message box custom action also need to be deferred, but issue is that how can we get message box result when we're running it deferred? because we cannot set installer property on deferred custom action.
We can show message box on the custom action code itself, this runs separate exe for migration, but issue is that message box will not be modal against the installer UI so it shows on top of the installer dialog but can go behind it
Please advise on how to proceed