I think another problem is there.
Conveting APE -> FLAC or mp3, the files get created, but the extension is in the wrong place.
I am using APE with CUE file, so conversion creates just the files, no import done. After conversion, the ape files are removed from library, and the flac files are imported. This way, it worked since the days of MC12.
Now it creates files like {Ape File Name}.flac ({TrackNumber} {TrackName})
The extension is no more a flac, so MC does not recognize it while trying to import.
Workaround is to manually move the misplaced ".flac" to the end of file name in Windows Explorer. Then import works, and the files are OK.
Converter options are:
Destination - Same as original
Mode - Leave original, do not add destination
Options - Number of files to convert at the same time: 4 (the computer is a quad one)
No Skip if destination already exist
No Skip if orig and dest are same type
I think, Encoding options are not relevant, because the same problem exist with FLAC and mp3.
The system is Vista x64 Ultimate, no big changes to the system since it last worked. Build 166, and 167 are the versions that I can confirm to have this problem.