It prooves that there is no metadata - there is audio data but it is messed up somehow.
So use mp3diags or other tools to repair the files and retag them.
Ok, I'll go try to repair but to me, if there is no metadata, after checking all bits in the file, then no metadata. Why do I see them in file properties? Is MP3Tag more strict on how it parses? I'm still to learn how it works.
Also MP3VAL says all MP3s i scanned in MP3DIAG are OK.
mp3val checks the integrity of the file. It does not care if there are any tags (although it sometimes mentions it).
As mp3diags finds a couple more errors with broken streams and such I would put the blame on these problems. there may be remains of tags but either they are not accessible or they are there but the audiodata will end abruptly or something like that.
Why such things happen and which program messed it up - don't ask me.
Right clicking on mp3 file and then click Properties I got this in TAG group. Just a quick check before downloading other mp3 diagnostics programs for details.
BAD ID3v2 is indicating that Mp3tag detected an ID3v2 tag that it was unable to parse correctly.
I'm guessing that it's simply a broken file and I'm marking this report as [X] No Bug. If you encounter any issues in this regard where you think that it's an issue in Mp3tag which needs to resolved, please come back and we'll investigate further.