I find that my files that have question mark “?” on the filename all failed to be imported.
I also remember that one of the issue we had on the forum with importing is because they have “/” on the filename.
this is good advice in general… different filesystems, different operating systems, different sharing mechanisms, and different software will all fail if you use any of these characters. if you can avoid spaces, backticks ( ` ), dollar signs ( $ ), and tilde ( ~ ), that’s a good idea too.
Wot? No spaces? That’s taking things a bit far, isn’t it? Almost without exception all my folder and track names use spaces. That’s for albums that I’ve ripped myself, and for music purchased from download sites…