https://bugs.winehq.org/show_bug.cgi?id=53306
--- Comment #1 from Rafał Mużyło galtgendo@o2.pl --- If I were into guesses (which I kinda am), I'd say you need either lib32-gst-libav or a specific 32bit wmv plugin (IIRC gstreamer has one, but gst-libav should cover it regardless).