You cannot exactly convert a playlist file (in this case .m3u file) to an actual audio file (for example .mp4). Playlists just contain references to the location of the audio files, not the audio data itself. At best you can open the playlist in a text editor like Notepad and check the path to the audio files where you can find them.
This conversion entry was verified by us and conversion was flagged as wrong or not possible.
Usually this happens when the conversion would try to convert different types of data between each other, such as audio to image, or it is not possible because incompatibility between programs, caused by closed file formats, very limited support etc.
If you find entry that you feel is flagged as bad wrongly, please tell us in the discussion below with as much as information as possible so we can fix it.