To verify errors of scan, we can use also "scan result" as Ludek said here : http://mediamonkey.com/forum/viewtopic.php?f=30&t=93700#p455189

But for me unknown length or zero length are not in the scan log.

But these last observations are no longer directly related to bad extensions, but files not recognized by mm5 or having integrity errors.
Sometimes a conversion will be enough but not all software can repair the same thing.

When length=unknown, we can detect them.
(length= 0 is different but mm5 can't read it before conversion.)

So by this way i see problems with other tracks.
Maybe it's will be a good idea to have a function to check the integrity of tracks.

Hi,
to clear few things. VLC is using stream decoding on their own custom decoders which means that VLC is only applications that I know is capable to recognize file by stream itself which is unique feature and which is completely reasonable taking in count number of VLC developers https://www.videolan.org/videolan/team/ also it is an open source project. We can only determine such issues if they are reported and usually fix them accordingly.

FYI you can easily Determine MPEG -> MP3 if you search MPEG files in MMW where Length is >1 Minute and File size <10MB.

Thank you for report.

If a track has a bad extension (mpeg for mp3; avi for mp3, mp3 for flac) then MM5, MM4 can neither play it nor index it correctly.
Try to manually change an extension and the piece of music becomes non-executable!
VLC succeeds in this a contrario.

MM5 seems to be suspicious by starting the Thumbnails generation again each time it is restarted.
And these indexing errors consume repeated resources without offering any possibility of correction.
I don't know if there are any routines or applications that can find files with such false extensions.
This could be useful.

Voilà pour cette information

see also : https://www.ventismedia.com/mantis/view.php?id=15372