To make Microsoft’s obsolete Silverlight plug in work with Firefox on Linux there are work-arounds available.
First, Chrome can be made to work with some Silverlight sites using https://ieonchrome.com/welcome?install. Unfortunately it seems to fail with some site that want to open in a new window or popup. Test it.
Back to Firefox:
Install Wine
http://pipelight.net/cms/install/installation-ubuntu.html
sudo add-apt-repository ppa:pipelight/stable sudo apt-get update sudo apt-get install --install-recommends pipelight-multi sudo pipelight-plugin --update
http://pipelight.net/cms/plugin-silverlight.html
sudo pipelight-plugin --enable silverlight
Check for install errors
pipelight-plugin --system-check Some websites will show you an error that your operating system is not supported. To get around this problem, you will need to install an user agent switcher as described here.
https://addons.mozilla.org/en-US/firefox/addon/user-agent-overrider/