This checks the state of your library database and music files. Errors are shown in red and warnings in green.
These are the errors and warnings you may see, and how to fix them:
Missing Music File
The music file is in the database, but was not found in the music directory. This can happen if the file was renamed, moved or deleted from the music drive/directory by another music player or File Explorer. You should always use the Music Library Manager to rename or delete music files. To fix it, either remove the missing track from the database by using Delete Selected Tracks; Import the file from your incremental Backup (did you make one?); or use Explorer to try to find the file and copy it back to the right place.
Music File Not In Library
A music file was found on the music drive/directory, but it's not in the music database. This can happen if you copied music files into your music files directory without using the Import Music Files feature. To fix it, just use Add Music Files to add the tracks back to your database.
A folder in your music directory has no files in it. This can happen if you have manually deleted the music files or used some another application to rename them. To fix it, use File Explorer (F12) to delete the directory. Check it really is empty first, in case you delete the wrong directory by mistake. Or you can leave it there, it won't cause any problems.
Missing Artist/Album/Track Name
The album, artist or track name is missing from the database. Use Edit Track Details to correct it.
Possible Duplicate Artist • 'xxx' and 'The xxx'
Very often the same artist is entered with and without "The", e.g. "The Rolling Stones" and "Rolling Stones". One of them is wrong and should be corrected. To fix it, do a filter by text for the artist name without "The", e.g. "Rolling Stones", select all the tracks on the offending album (press Ctrl+A), then rename the artist (press F6 or Ctrl+F6) by adding or removing "The". If more than one album has the wrong name, do this for each album.
Invalid Relative Path
Somehow an entire artist or album directory is missing or has been renamed. Take a look with Windows File Explorer (F12) and see if you can find it and move it back again. Or restore it from your backup. You did make a backup didn't you?
The same track is in the library more than once. Remove the unwanted tracks with Remove Selected Tracks. Note: This warning does not occur if the file types are different, e.g. you can have '.wav' and '.mp3' versions of the same track.
Invalid Artist/Album/Track Name
The name is obviously invalid, e.g. "?????". This can happen if the tags in the music file are corrupted, often by a buggy application with incorrect handling of incompatible character sets. Use Rename Artist/Album or Edit Track Details to correct it.
Alien Invasion In Progress
This error is unlikely to occur very often, but we must be prepared. Contact your planet's military establishments as soon as possible, then arm yourselves and hide in the basement to await further instructions. Don't forget to take your music library with you!