If unable to resolve through drag & drop you can do an interface reset: http://www.mediamonkey.com/support/index.php?/Knowledgebase/Article/View/151/0/reset-mediamonkey-for-windows-interface-to-defaults

I can position the player controller anywhere on the screen other than the bottom of the Mediamonkey program (the original position)! If I do then the player controller is not usable - It is cut off by the title/artist/album window!

Works fine here. The Player is extended the whole width of the program. Drag & Drop to accomplish this may take a few trial & errors though.

Just installed the newest 4.1.19.1859 build of MM, on Win10.

I like to have the player window of MM at the bottom, spanning the whole width. But that is no longer possible in this new build. I can only nest it in a couple of areas (e.g. under the Media Tree pane, see screenshot), or have it as a pop-up.

[img]https://www.dropbox.com/s/swksbvcgteiz2k1/cap%202017-11-06%2023.5255.jpg?dl=0[/img]