Total Commander

I am having problem opening the network mkv file with my media player(BS Player or VLC) as it will always open with Opera browser if I open it from Total Commander. This happen only when I open it from my network but have no problem if the mkv file is on my smartphone. Is there a way that I can select "open with" just like on Lollipop as I am on Mashmallow now. The only way I can open with my media player is to uninstall the opera browser with I don't wish to as Opera is my default browser.

On Android, the target app (e.g. player) defines which file types it supports. You can define a custom association (which will work only inside of Total Commander: Main menu - Configuration - Internal associations.