[BUG] Duplicate media when using MetaMix causing import errors

[insanelow]

Tubifarry Version

v2.0.3.0

Lidarr Version

v3.1.2.4928

Operating System

Docker

Bug Description

Importing some releases fails due to duplicate media with the same number

Steps to Reproduce

1. Activate Deezer as metadata source
2. Activate MetaMix
   1. Lidarr Default (Priority 1)
   2. Deezer (Priority 10)
3. Add Artist (for example Bob Marley)
4. Get release
5. Import release

Expected Behavior

Release gets imported without errors

Trace Log Files

Logs

2026-03-29 11:31:18.4|Info|ImportApprovedTracks|Importing 31 tracks
2026-03-29 11:31:18.4|Trace|EventAggregator|Publishing CommandUpdatedEvent
2026-03-29 11:31:18.4|Trace|EventAggregator|CommandUpdatedEvent -> CommandController
2026-03-29 11:31:18.4|Trace|EventAggregator|CommandUpdatedEvent <- CommandController
2026-03-29 11:31:18.4|Debug|ImportApprovedTracks|Importing 31 files. replaceExisting: True
2026-03-29 11:31:18.4|Warn|ImportApprovedTracks|Couldn't import track /data/music/Rastaman Vibration (9e64450d-608d-3d85-b881-9b1de24f9195)/Bob Marley & The Wailers_Rastaman Vibration_01-01_Positive Vibration.flac

[v3.1.2.4928] System.InvalidOperationException: Sequence contains more than one matching element
   at System.Linq.ThrowHelper.ThrowMoreThanOneMatchException()
   at System.Linq.Enumerable.TryGetSingle[TSource](IEnumerable`1 source, Func`2 predicate, Boolean& found)
   at NzbDrone.Core.Organizer.FileNameBuilder.BuildTrackFileName(List`1 tracks, Artist artist, Album album, TrackFile trackFile, String extension, Int32 maxPath, NamingConfig namingConfig, List`1 customFormats) in ./NzbDrone.Core/Organizer/FileNameBuilder.cs:line 127
   at NzbDrone.Core.MediaFiles.TrackFileMovingService.MoveTrackFile(TrackFile trackFile, LocalTrack localTrack) in ./NzbDrone.Core/MediaFiles/TrackFileMovingService.cs:line 86
   at NzbDrone.Core.MediaFiles.UpgradeMediaFileService.UpgradeTrackFile(TrackFile trackFile, LocalTrack localTrack, Boolean copyOnly) in ./NzbDrone.Core/MediaFiles/UpgradeMediaFileService.cs:line 41
   at NzbDrone.Core.MediaFiles.TrackImport.ImportApprovedTracks.Import(List`1 decisions, Boolean replaceExisting, DownloadClientItem downloadClientItem, ImportMode importMode) in ./NzbDrone.Core/MediaFiles/TrackImport/ImportApprovedTracks.cs:line 241

Log Checklist

• I have enabled Trace logging in Lidarr before reproducing the issue

Screenshots

Screenshots

Additional Context

No response

[TypNull]

This seems to be expected behavior. If you have duplicate entries for the same artist and albums and you’re not using the MusicBrainz one to enhance with other metadata, Lidarr will handle them this way. I don't think there is a direct fix for this on my end.
You’ll need to choose one artist entry or merge them to avoid conflicts

[TypNull]

But I will still look into it later today, if there is a way to fix this

[insanelow]

Thanks for the quick reply.

What do you mean by 'not using MusicBrainz'? I thought Lidarr default is using MusicBrainz as metadata source.
I don't have duplicate albums listed under the artist, but rather it duplicates the media for the affected albums, so merging the affected metadata seems to at least work partially.
Also you mention merging the entries. How would I do that? I couldn't find any hint towards that in the UI, or docs.

[TypNull]

Lidarr default uses MusicBrainz as its metadata source. The problem you are likely running into is that by enabling Deezer you ended up with two separate artist entries, one from Deezer and one from MusicBrainz. When Lidarr then tries to find the artist for the release you want to import it finds both of them and throws the error you are seeing because it expects only one match, at least that is currently my guess that you have the same artists twice.

The correct setup would be a single merged artist where MusicBrainz is the base and Deezer fills in any missing albums. Having two separate artists with the same releases causes this conflict. MetaMix does have an option for merging the Deezer and MusicBrainz artists together since they come from different sources and have different identifiers internally. I think the issue is specifically about how the file name builder handles this situation. I have not dug into that part yet but I will do so later today.

Before I investigate further I just want to make sure I understood your setup correctly. Do you currently have only one artist entry where the albums are already merged together and file renaming is enabled, meaning you do not have two separate artist entries with the same name, one from Deezer and one from MusicBrainz?

[insanelow]

Correct, my library shows me only one entry for each artist with albums from MusicBrainz and Deezer merged. When I open the album in question it shows me more media than it should have. For example under Bob Marley I see the album Rastaman Vibration only once, but with two media, each called 'Digital Media 1' and both listing the exact same tracks.

Here's my config for better reference:

• Metadata Consumers

  • Lidarr Default
    • Enabled
  • Deezer
    • Enabled
    • User Agent configured
    • Page Number: 1
    • Page Size: 10
    • Cache: Permanent
    • Cache dir: /config/cache/deezer
  • MetaMix
    • Enabled
    • Priority Rules
      • Lidarr Default: 1
      • Deezer: 10
    • Maximum usabe threshold: 15
    • Dynamic threshold: off
    • Storing Path: /config/cache/metamix
    • Artist Query Timeout: 30
    • Multi-Source Population: enabled

• Media Management

  • Track Naming
    • Rename Tracks: enabled
    • Replace Illegal Characters: enabled
    • Colon Replacement: Smart Replace
    • Standard Track Format: {Album Title} ({Release Year}) {Album Type}/{Track:00} - {Track Title}
    • Multi Disc Track Format: {Album Title} ({Release Year}) {Album Type}/{Medium Format} {medium:00}/{Track:00} - {Track Title}
    • Standard Track Format: {Artist NameThe}

[insanelow]

Out of curiosity I checked my whole library again and it seems that it indeed also added two duplicate artists. I assume those two duplicates come from me manually adding two albums, which weren't listed under the main artist.

Edit: Both artists aren't related to the artists I have trouble with.

[TypNull]

Sometimes the fix is surprisingly simple. I had a single character wrong and that caused the filename builder to complain. It’s corrected and will be in the next release.