Verify Java is associated with JNLP files using the Java Control Panel window. Open it by clicking "Start," selecting "Control Panel," clicking "Programs" and clicking the "Java (32-bit)" option.

Open About Java to see the Java version. Set the security level within Java Control Panel Several times, an untrusted Java application by an unknown publisher is included in the webpage.

How to install Java on your computer. To run Java apps, open JAR files or compile some source code into bytecode you’ll need to install Java. To download and install Java on Windows, MacOS or Ubuntu, ...

To clear the Java cache, open the Java control panel, which you can find in the Windows Control Panel or in System Preferences on a Mac. You can also try deleting the temporary internet files ...