http://bugs.winehq.org/show_bug.cgi?id=31413
--- Comment #9 from gat gatlinsullivan@yahoo.com 2012-08-07 22:57:55 CDT --- I get the dialog about one of my several .mkv files. Why only one? I don't know. The majority are .ogg, but I can't see the files after, but they're there. It reads that we've the same problem to me. (I convert all of my .mp3 files. If I really need to test with one, then I can get one...)
On Fedora 17's Wine (wine.x86_64 0:1.5.8-1.fc17), I re-installed Wine and Nightingale. Before that, I removed ~/.wine/, ~/.local/share/wineprefixes/, & ~/.cache/winetricks/. With this new set I crashed while importing the ~/Music which contains my .mkv. (The wineprefix held your suggestion for win32; I never did anything with winetricks though - so it shouldn't have mattered) The only thing that I did after re-installations was "wine Nightingale_1.11.0-2223_windows-i686.exe".
Repeating, I simply removed ~/.wine/ only and re-installed Nightingale. I had crashes after every import. I first tried ~/Music/. I then tried only one folder with just .ogg files ( about 12 of them ). Neither worked. I was removing ~/.wine/ after every attempt.
I am concerned that this may not simply be a bug with Wine. It could be a bug with Wine &/or Nightingale (https://github.com/nightingale-media-player/nightingale-hacking/issues/65#is...).
Between the uncertainty above and Fedora not hosting a whole bunch of versions of Wine. It will be a little bit till I do regression testing. I am working on a script. It will use Wine's source. This is probably preferred because I've read some contention about using Fedora's builds and bug testing with them since they're not officially supported.