Java web start

Please could you tell me how to solve this java error. Do I need to download additional software

Code:estelle@estelle-H81M-S2H:~/Documents$ javaws qs.jnlp
selected jre: /usr/lib/jvm/java-16-oracle
WARNING: package sun.applet not in java.desktop
WARNING: package com.sun.net.ssl.internal.ssl not in java.base
WARNING: package javax.jnlp not in java.desktop
Exception in thread "main" java.lang.NoClassDefFoundError: sun/awt/AWTSecurityManager
at net.sourceforge.jnlp.runtime.JNLPRuntime.initialize(JNLPRuntime.java:261)
at net.sourceforge.jnlp.runtime.Boot.init(Boot.java:349)
at net.sourceforge.jnlp.runtime.JnlpBoot.run(JnlpBoot.java:58)
at net.sourceforge.jnlp.runtime.Boot.run(Boot.java:270)
at net.sourceforge.jnlp.runtime.Boot.run(Boot.java:63)
at java.base/java.security.AccessController.doPrivileged(AccessController.java:312)
at net.sourceforge.jnlp.runtime.Boot.main(Boot.java:210)Regards Troysie