The ability to open PDF files is an essential need on any smartphone. Following the February 2018 update, Windows 10 Mobile users in the production ring were unable to open any PDF file using Microsoft Edge, the default PDF reader for Windows 10 users. After lots of complaints from users, Microsoft has finally acknowledged the issue and they announced that they are working on a fix for this issue.
Thank you for letting us know. You may encounter issues when trying to access PDF files on Microsoft Edge after the latest update on Windows 10 Mobile. We are aware of the issue and our developers are working to resolved it. Rest assured that there will be an update in an upcoming release.
Until you get this update from Microsoft, you can download and install any available PDF reader apps from the Store.
Thanks to Hussien and Guido for the tips.