foobar2000 v0.9.2
I have installed both foo_browser and foo_playlist_tree.

There are now two tabs: Default and *Browser*.
With *Browser* selected all existing tracks are shown and - as is - it already represents an enormous advance in terms of tag checking for correction etc.
However, the features that attracted me first I don't know how to activate (showing different panels).

Looking at File | Preferences | Media Library I see that there are three Installed Media Library viewers, namely:
Album List
Browser
Playlist Tree Panel.
However, the Activate button is dimmed for the two latter viewers.
This may be the reason why Album List is the only effective option, but how to be able to activate the others?