I have tried to create a custom action for a Visual Studio Installer project to modify the permissions for a config file.
The Installer.cs is as follows:
Sometimes, "Debugger.Launch();" is put at those overwritten functions for debugging. If you build the installer with the statement there, and during your installation, a dialog will popup to ask you whether debug is needed, if you press 'cancel debugging', you'll get this error dialog. Because you added the 'Debugger.Launch()' at your function, then that function will be considered as 'missed' by installer. So, don't forget to remove it.