Death mikegonzalez2k,
I tried to install an older version of VLC on my tablet and on my Fire. I used 3.4.0 on my tablet (Android 7) then, when VLC requires username and password, I wrote only the password on the tablet and the app works fine! Unfortunately this is not the case for Amazon fire: I tried also even older versions, but, for example, if I want to see a movie from PC to TV, I have to insert the password many times: to access to my PC, to open the primary directory, then to open the secondary directory, and finally to open the file...
Disconsolate greetings