When logging in from a Mozilla Firefox 52.x browser on a supported Windows OS or macOS client, Pulse Secure products use a Java applet to install client components (for PCS 8.1RX and prior) such as the Pulse Secure Desktop Client, Network Connect, Windows Terminal Services, etc. In 8.2RX and above, Pulse Secure products had introduced Pulse Secure Application Launcher (PSAL) as an alternative to Java for deploying Pulse Secure components. As of today, Java Secure Application Manager (JSAM) and Premier Java RDP Applet remain the last components to leverage Java in 8.2RX.
Mozilla announced that on March 2017 support for NPAPI will be disabled by default in Firefox 52.X. Refer to this link for more details:
https://support.mozilla.org/t5/Problems-with-add-ons-plugins-or/Why-do-Java-Silverlight-Adobe-Acrobat-and-other-plugins-no/ta-p/31069What is the impact of this on Pulse Secure Products?Once NPAPI plugins are disabled, end-users will not be able to install or launch Pulse Secure components from Mozilla Firefox 52.X and above.
What is the actual end-user experience? The client install and/or launch process will not complete. The end-user experience will be similar to what it is when Java is not enabled on Firefox.