Wow -- thanks a lot for the quick reaction!
ok, mayby I have to go for the longer story. I already had the plugin installed once, but whenever clicking on an album afterwards I just got a totally blank page as result. That's why I de-installed the plugin.
Now I when wanted to re-install, I had the problem described above, and thanks to your hint of using debug mode, I got the following error message:
While executing query "insert into cpg14x_plugins (name, path,priority) values ("Album Addfav","album_addfav2",6);" on 0
mySQL error: Doppelter Eintrag 'Album Addfav' f�r Schl�ssel 'name'
[the German mySQL error says that the key in 'Album Addfav' is doubled] Thus, I assumed that the previous un-install wasn't well completed, so I deleted the folder 'album_addfav' in the \plugin subdir and re-copied it. Now the plugin could be installed, at least the plugin-mgr says so, but I have the known problem blank albums again. I even don't get any output of the debugging console on those blank pages -- maybe you could have a look at it yourself?
Vielen Dank bereits für Deine Hilfe!!