I am on a raspberry pi with ubuntu mate on a pi 3 and I need to install the latest adobe flash player for chromium. When I click on a certain video it says I need the latest adobe flash player.
Open the Software Boutique (make sure this is updated to latest version). Go the the Internet category and the very first thing on the list is Adobe Flash Player.
If that doesn't work, try this.
I did the tutorial you sent me and it still says I need the latest adobe flash plugin player also it takes me to this.