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.

Since JNLP files are simply Java Web Start files that open applications through an Internet browser, any browser that works in Windows 8.1 will open a JNLP file as long as you have Java installed.

What is a sandbox? This first sandbox that most Java developers collide with is the one that contains applets within a Web browser. The default behavior, the most restrictive one, prohibits almost ...