http://bugs.winehq.org/show_bug.cgi?id=58286
--- Comment #1 from Ken Sharp imwellcushtymelike@gmail.com --- Created attachment 78635 --> http://bugs.winehq.org/attachment.cgi?id=78635 Console
I missed an important point:
wineboot = OK WINEARCH=win32 wineboot = OK WINEARCH=win64 wineboot = fail WINEARCH=wow64 wineboot = fail
So it's when WINEARCH is forcing a new 64-bit wineprefix.