So I've been having troubles playing videos on my device, both on the webplayer and videos that I've downloaded. The webplayer suggests me to download adobe flashplayer and so I did, following this wikihow https://www.wikihow.com/Upgrade-Adobe-Flash-Player-on-Linux-Mint

When done the webplayer kept giving me messages of installing adobe flash. So I went to adobes website and tried downloading it directly from there, but it says it is already installed.

When it comes to files on the computer this happens: "The file "X.mkv.part" has no known programs associated with it.  If you trust the source of this file, and have sufficient permissions, you can mark it executable and launch it.  Or, you can use the Open With dialog to pick a program to associate it with"

Im clicking make executable and run, but nothing happens. So instead I go for the other option, choose a program, and opens it with media player. Then I get the message "An error occurred, the file is in wrong format."

So, how do I progress from here? What format should it be in and how do I get the webplayer to work?

Thanks!