cannot access local media via link in vuforia view

I try to access a pdf file, or a mp4 video file, trough a link-widget.

It works in preview mode on my notebook and on the tablet, but not in the Vuforia View App. 

I'm using an Windows 10 Tablet with the Vuforia View App, and when I click on either the pdf-link or the video-link in the app I get an Windows 10 popup with text "You need a new app to open this ms-local-stream"

Someone has an idea how to fix this?