With the latest build of Windows 10 (19042) the app.alert functionality no longer works inside of IE 11 (yes, we are moving away from IE 11) when the PDF is presented inside of the browser. The sound notification is present but the pop up box no longer shows up. I've rolled back to the previous Windows 10 build and it works. Has anyone encountered this or have any ideas on how to program it to work?
In case someone encounters this issue in the future. Here is a workaround. Adobe Reader DC must be installed AND set as the default.Open Adobe Reader DCFrom the menus, select “Edit” then “Preferences”In the preferences dialog, select “Security (Enhanced)” from the list of categoriesIn “Sandbox Protections” uncheck “Enable Protected Mode at startup” Something in the latest build in Windows 10 broke this process. Nevertheless, here is a solution.