This phenomenon is quite common after the release of Java 7.
How do I know if Java is enabled in Firefox? Under Security click on Mixed Code and check the “Disable verification” box.
From the list of options that will be displayed expand the Security one.Open Java Settings within Control Panel.
#Older java plugin for firefox how to
How to disable the Java “Security Warning” popup in Windows 10, 8 How do you disable Java security warning do you want to run this application? Now wait for the Java prompt to appear.Click or double-click the Firefox app icon, which resembles an orange fox around a blue globe.