I am trying to use Firefox as web browser to configure a managed switch.  This can require JRE 1.6 or later.
I have installed Firefox 52.4.0 (32 bit) from antix repo but am really stuck getting the java plugin installed and working.
Please could somebody help me get this working?
Budgie

applicable to firefox version 52esr:

in firefox urlbar, type about:config
create a new preferencekey by right-clicking middle of the page and, from context menu, choose New -> Boolean
preference Name: plugin.load_flash_only
value: false

Install debian package"icedtea-plugin" via synaptic, or via antiX ControlCenter --} System --} Meta Package Installer
(in metapackage installer, icedtea is listed under"Misc". May need to first visit the"non-free" tab)

Hi and very many thanks for prompt reply.  Your answer is concise and clear.  No joy with non-free when using the Meta Package installer.  When I try and install non-free I get a red message
"firmware needs non-free" and if I press button nothing is installed so no menu item for icedtea-plugin. 
Had a look at the installation repos and non-free is enabled so I have no idea what problem is.  Possibly some driver issue.
Used cli and installed using apt-get install and all seemed ok.

Even with firefox config changed as you suggest I still get"You need the Java Plugin.  Get it from here" when I try and use device view on switch configuration.
Any ideas what I am doing wrong?
Thanks again,
Budgie

The"firmware needs non-free" message suggest that you (inadvertently, perhaps) may be running a"libre" kernel.
What is the output of uname -a ?
If it contains substring"libre", AFAIK you will be unable to install non-free unless you install a different kernel.

If it's not a libre kernel, and you are using antiX16, you might not have the latest version of packageinstaller
(in which the confusingly separate"non-free sources" ui tab is absent)

you might try (disclaimer: I haven't tested)
1) retrieve the
========= SCRAPER REMOVED AN EMBEDDED LINK HERE ===========
url was:"http://repo.antixlinux.com/stretch/pool/main/p/packageinstaller/"
linktext was:"newer version"
====================================
packageinstaller
2) sudo apt purge install-meta-antix
3) sudo dpkg -i /path/to/downloaded/packageinstaller_xxxxxxx.deb
4) {while web browser is not running} launch packageinstaller, expand"Misc", tick"Java and blahblah icedtea", click"Install" button
5) launch browser, visit"Tools --} Add-ons", click"Plugins", verify the IcedTead selectbox is set to:"Ask to Activate" or"Always Activate"