How to Open a JNLP File. Oracle's Java plug-in supports Java Network Launch Protocol files, which point to Java applets or applications. With Java installed, you can click a link to a JNLP file on ...

To fix the JNLP file not opening problem, update or install Java Runtime Environment, set JRE as the default app, or install JRE 64-bit.

To fix the JNLP file not opening problem, update or install Java Runtime Environment, set JRE as the default app, or install JRE 64-bit.

If you're using Application Guard on Edge, these are the steps to allow file download to your physical device running Windows 10 Pro or Enterprise.

Windows Defender setting In Windows Defender, you can also change Edge's SmartScreen to merely warn you when you are about to download a file it deems suspicious instead of it outright blocking it.

While some browsers, such as Internet Explorer, launch JNLP files in the browser window automatically, Chrome just downloads them, making you launch them manually from the download menu.