https://bugs.winehq.org/show_bug.cgi?id=44470
--- Comment #2 from Géza Búza bghome@gmail.com --- (In reply to Fabian Maurer from comment #1)
Does that also happen in a clean WINEPREFIX? Because winecfg shouldn't even use that.
That does not make a difference.
Also, did you install both 32 and 64bit versions of the library?
Well, no only the 64-bit version is present. Installing lib32-mpg123 makes the error go away. However when I run winecfg by defining the architecture to 64 bit, like WINEARCH=win64 WINEPREFIX=~/.wine winecfg, and I expected it to use only 64-bit binaries in this case.