hi, such plugins aren't supported in firefox anymore since version 52: Why do Java, Silverlight, Adobe Acrobat and other plugins no longer work?

So this isn't needed to "Block dangerous and intrusive Flash content" as it states? There is a Shockwave Flash, Java and a Silverlight also in the Add-ons; Plugins and they all updated recently. So I'm assuming my best move is to leave them all alone at this point until an issue causes another action to be taken. I still don't know why it's there and what it does but the browser is working remarkably well so no matter.

Thank you for responding Philipp