JNLP file not opening / not launching automatically [Fixed]

by Tashreef Shareef
Tashreef Shareef
Tashreef Shareef
Windows & Software Expert
Tashreef Shareef is a software developer turned tech writer. He discovered his interest in technology after reading a tech magazine accidentally. Now he writes about everything tech from... read more
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  • JNLP file is associated with the Java Web Start program and helps launch applications from a remote desktop client.
  • Misconfigured file type association or missing Java Runtime Environment can lead to JNLP file not opening problems.
  • Windows 64-bit users may require to install the 64-bit JRE version on top of their existing JRE installation.
  • You can also set the default app for JNLP file type from the Default Apps settings.

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Windows OS, by default, associates each file with an application that runs it.

JNLP (Java Network Launch Protocol) is a file format that enables an application to be launched on a client desktop by using a remote web server.

However, several users have reported the JNLP file not opening issue when trying to access the file. Even if you have the required software to open .jnlp file, it may fail to launch automatically.

Since the JNLP files are program-specific, your computer may fail to recognize the software required to execute the file.

In this article, we take a look at what is a JNLP file format and how to resolve the JNLP file not opening problem in Windows computers.

What is a JNLP file?

How to open JNLP file

Java Network Launch Protocol (JNLP) format contains information such as the remote address for downloading a java program and other classes. JNLP files are used for launching and managing Java applications over a network.

JNLP files are usually in the XML file format. To view and edit the file, you must have a text editor with the XML file format. To execute the file, your computer must have Java Runtime Environment installed.

While JNLP is part of Java Web Start technology, it comes bundled with Java Runtime Environment to open the JNLP files.

How do I open a JNLP file in Windows 10?

JNLP not launching automatically
  1. Download and install Java Runtime Runtime Environment. Run the installer and follow on-screen instructions to install the program.
  2. Right-click on the JNLP file that is not opening and select Open With.
  3. In the ‘How you want to open this File’ window, scroll down and click on Look for another app on this PC option.
  4. When the File Explorer window opens, navigate to the following location:
    C:\Program Files (x86)\Java\jre1.8.0_261\bin
  5. Select javaws.exe and click the Open button. This will open the JNLP file as intended.
  6. Make sure to check the Always use this app to open .jnlp files option in the How do you want to open this file window to save JRE as the default app to open this file.

If the JNLP JNLP file is still not launching, proceed with the next set of steps below.

Install 64-bit JRE edition

JNLP file not opening
  1. Visit Java download center.
  2. Scroll down and click on Windows offline (64-bit) link to download the offline installer and wait for the download to complete.
  3. Once the download is complete, double-click on the installer to run it. Follow on-screen instructions to install the app.
  4. Once installed, reboot the computer. After the restart, try opening the JNLP file and check for any improvements

If you are using a 64-bit edition of Windows, you may need to manually download and install the 64-bit JRE version. 

Several users have reportedly fixed the JNLP file not opening problem by installing the correct edition of the Java Runtime Environment.

How do I run a JNLP file in Windows Command line?

JNLP file not opening
  1. Select a link on a Web page that refers to a .jnlp file. If your browser does not have the correct association to run Web Start applications, select the install_dir/jre/bin/javas command from the Open/Save window to start the Web Start application.
  2. Next, in the command prompt, type the following command and hit enter to execute:
    Javaws <URL>
  3. In the above command, <URL> is the location of a .jnlp file.

How do I automatically open JNLP files?

JNLP file not opening
  1. Press the Windows key + R on your keyboard to open Settings.
  2. Click on Apps.
  3. From the left pane, click on the Default Apps tab.
  4. Scroll down and click on Choose default apps by file type.
  5. Scroll down to .jnl file type and click the Choose a Default button.
  6. Select Java(TM) Web Launcher.
  7. Close the Settings window and open File Explorer.
  8. Now locate and double-click on the JNLP file to see if it opens automatically.

Windows system requires JRE to run JNLP files. At times, if the file is associated with other programs, it may result in the JNLP file, not opening problem.

Installing JRE or manually choosing the default file association in settings can help you resolve the issue.

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