I think that the button is not implemented yet. To play the movie you can use the Grid. Just click on any movie and use the popup menu. There is the function to play it.
In order to achieve what is possible, you have to try the impossible over and over again. Hermann Hesse
i tried on the new alpa 8.0.0.12 it seems to work only with files on the pc which has xmm installed, it doesn't work with movies on another pc in the lan. popup and html play them right. then i looked in the file manager(movies) and seen that all files on other lan drives are checked as missing, should i do something to show xmm they really are there?