Bug: Emby shows no art on all media entries that existed when the metadata directory was unmounted

[gu5gus 1]

Hello, I found a bug. The bug is that Emby shows no art on all media entries that existed when the metadata directory was unmounted or otherwise made unavailable to Emby (e.g. permissions). It appears that this bug has been around for a long time because I found mention of this behavior from many years ago. It is explained below.

Steps to reproduce:

1. Create a server and store your metadata on a separate network share from your media collection.
2. Scan your library, populating the media entries with artwork.
3. Unmount your metadata share or otherwise make it unavailable. I'm not sure how long the metadata has to be down for this to be reproduced. For me the metadata share was down for a day or two.
4. Use an Emby client to browse the library. The media entries are in the library but no artwork is shown as expected.
5. Remount your metadata share.
6. Add new media to your library.
7. Observe the following:
   1. The new media works just fine, artwork is shown as expected.
   2. The media that was in the library at the time of being unmounted will never be shown with artwork again. I say never but it has been about 2 months with nearly daily use.
   3. This is resolved by choosing to refresh the metadata for a media entry and choosing to redownload all artwork. After doing this, that media will now show artwork.

For many of us it is not reasonable to redownload all artwork for all affected media. 

 

Expected behavior:

Media that is tagged as its artwork no longer available should have its artwork redownloaded at the next library scan. 

 

Logs are attached in case they're useful. If there is a command somewhere to mass redownload artwork I would love to know about it. 

emby no art after metadata was unmounted.zip

[gu5gus 1]

I should add that in step 3, a library scan has most likely occurred while the metadata share was unmounted. 

[gu5gus 1]

Update: It looks like some of the art of the media that was in the library at the time of the metadata share having been unmounted is now showing up in the library. I counted, of 234 items only 63 had media showing, that's 27%. I think this was probably like this all along and I only now noticed it.

[Luke 42528]

HI, I think if you run a normal library scan then the server should be able to rediscover it.

[gu5gus 1]

Hi Luke thanks for your reply. 

I have run dozens of manually executed normal library scans since the incident, and there have been automatic ones as well (I have been observing the server closely since the incident). Perhaps that's what recovered the 27% that are showing with artwork. 

I realize that I could just blow away the affected libraries and rebuild them from scratch but this would lose me hundreds of metadata customizations so I really want to keep this as a final option.

I'd be happy to run tests and gather logs if you have any further ideas.

Edited May 7 by gu5gus

[gu5gus 1]

I have also found that around 10 of my ~150 collections are missing. The remaining collections don't appear to have had their contents affected.

[gu5gus 1]

@Lukelook I get that to you this appears to be an isolated incident and so it isn't worth digging into. But there have been reports scattered throughout history of this exact problem. So there is clearly some edge case bug here. And with it being an edge case it is probably difficult to reproduce and therefore difficult to investigate. So it appears to me that this is a rare opportunity to investigate a UX-breaking bug that has been present in Emby for many years. I understand that in any case I will have to rebuild my libraries from scratch. But I'm absolutely willing to wait and first do the legwork to help you guys investigate this however is needed. Just give me instructions. 

Edited May 8 by gu5gus

[ebr 16430]

Perhaps @sa2000could help you take a look.

[sa2000 774]

On 04/05/2026 at 01:20, gu5gus said:

Logs are attached in case they're useful. If there is a command somewhere to mass redownload artwork I would love to know about it

What are times/dates when the metadata mount was unavailable and available again

Logs cover periods

2026-05-02 00:00 to 2026-05-03 16:00

and

2026-05-03 16:56 to 2026-05-03 17:05

 

 

[sa2000 774]

On 04/05/2026 at 01:20, gu5gus said:

• Create a server and store your metadata on a separate network share from your media collection.
• Scan your library, populating the media entries with artwork.
• Unmount your metadata share or otherwise make it unavailable. I'm not sure how long the metadata has to be down for this to be reproduced. For me the metadata share was down for a day or two.
• Use an Emby client to browse the library. The media entries are in the library but no artwork is shown as expected.
• Remount your metadata share.

I just did a test on windows which I hoped would be similar

Mapped a network drive to a share on another PC

The share has a folder where the metadata folder will be placed under

A new Emby Server (I used 4.10.0.11 Beta) created. Metadata Path set to the folder on the network drive and the metadata folder would be created below that by Emby Server

Created a TV Library

All metadata / posters / people images all ok when tested in Emby Web

Shutdown Emby Server

Disconnected the Network Drive

Relaunced Emby Server with the metadata path being unavailble 

Emby Web continued to display images (using what was cached from setup time)

Emby for iOS had no images at all

Shutdown Emby Server

Mapped Network Drive again to same root folder as before for the Drive

Relaunched Emby Server

Went back and forward on Emby for iOS

All images appeared ok

What was the difference in what happened with your metadata mount? Ought to be similar to the network drive disappearing and then re-appearing

 

 

 

Edited May 11 by sa2000

[sa2000 774]

4 minutes ago, sa2000 said:

What was the difference in what happened with your metadata mount? Ought to be similar to the network drive disappearing and then re-appearing

The difference could be that I did not run any scans or metadata refreshes whilst the network drive for the metadata path was disconnected

I will try that next

Edited May 11 by sa2000

[sa2000 774]

Further to my earlier tests

Scan of the library and metadata refresh with default options of the library whilst the metadata network drive was disconnected resulted in loss of all images in the clients

Shutting Down embt server, restoring the mapped drive and re launching emby server brought back the images for the TV Library that I had setup on this test server. 

The only missing image I can se if the composite image for the library - which would probably get recreated when I rescan the library

[sa2000 774]

After I did a library scan, the composite library image appeared

I do not know if this is because I did the test on the 4.10.0.11 beta

I will repeat the test on 4.9.3 tomorrow

[gu5gus 1]

Hi @sa2000

Thanks for taking a look! That I am even having this problem was a surprise to me because the emby server VM reboots regularly and never mounts on startup. So regularly it will be running with the metadata unmounted, and it probably also did library scans during that time too. I had been running it for years like this without a problem and then this happened. The instance of the metadata share being unmounted that coincided with the start of this problem was a week or two before the dates (May 2, 3) that you said were in the logs. If you could provide instructions I could gather logs manually that should cover that time frame.

My hypothesis is that something unique happened to the database that caused metadata to not be shown. The deletion of those collections I mentioned are perhaps corruptions of their entries in the database, and perhaps the missing artwork is also the result of corruption of the path entries for the artwork. I can share the sqlite database if someone tells me where to find it, or run commands to examine the paths for specific library entries if someone could provide the commands (I'm a little experienced with working with databases). 

Edited May 12 by gu5gus

[sa2000 774]

@gu5gus My tests on Emby Server 4.9.3.0 were ok as well - when the network drive was re-established following having it disconnected and running a scan whilst disconnected,  all the images came back except for the library composite image and that required a rescan of the library. So similar outcome to 4.10.0.11

Will need specific examples of a show / movie that had images before and no longer does after the metadata path was remounted and to have logs covering the time of viewing the media show / season or whatever lost the images

For the logs you provided the only image related error was to do with one media item not having a backdrop

There were logged errors to do with the media paths not being available

2026-05-03 16:57:57.379 Error App: Error in validateChildren for 33313 /mnt/media-library-ro/Audio Books, Radio Plays, Lectures
	System.IO.DirectoryNotFoundException: System.IO.DirectoryNotFoundException: Could not find a part of the path '/mnt/media-library-ro/Audio Books, Radio Plays, Lectures'.

2026-05-03 16:57:57.380 Error App: Error in validateChildren for 704464 /mnt/media-library-ro/Video/Comics & Magicians
	System.IO.DirectoryNotFoundException: System.IO.DirectoryNotFoundException: Could not find a part of the path '/mnt/media-library-ro/Video/Comics & Magicians'.

2026-05-03 16:57:57.384 Error App: Error in validateChildren for 575926 /mnt/media-library-ro/Ebook Library/
	System.IO.DirectoryNotFoundException: System.IO.DirectoryNotFoundException: Could not find a part of the path '/mnt/media-library-ro/Ebook Library'.

2026-05-03 16:57:57.385 Error App: Error in validateChildren for 704466 /mnt/media-library-ro/Video/Historical Cartoon Collected Works 1930-1970
	System.IO.DirectoryNotFoundException: System.IO.DirectoryNotFoundException: Could not find a part of the path '/mnt/media-library-ro/Video/Historical Cartoon Collected Works 1930-1970'.

2026-05-03 16:57:57.386 Error App: Error in validateChildren for 54116 /mnt/media-library-ro/Video/Live Music & Music Videos
	System.IO.DirectoryNotFoundException: System.IO.DirectoryNotFoundException: Could not find a part of the path '/mnt/media-library-ro/Video/Live Music & Music Videos'.

2026-05-03 16:57:57.387 Error App: Error in validateChildren for 3 /mnt/media-library-ro/Video/Movies
	System.IO.DirectoryNotFoundException: System.IO.DirectoryNotFoundException: Could not find a part of the path '/mnt/media-library-ro/Video/Movies'.

2026-05-03 16:57:57.387 Error App: Error in validateChildren for 672787 /mnt/media-library-ro/Video/Movies - Extras
	System.IO.DirectoryNotFoundException: System.IO.DirectoryNotFoundException: Could not find a part of the path '/mnt/media-library-ro/Video/Movies - Extras'.

2026-05-03 16:57:57.388 Error App: Error in validateChildren for 664612 /mnt/media-library-ro/Video/Movies - Rifftrax
	System.IO.DirectoryNotFoundException: System.IO.DirectoryNotFoundException: Could not find a part of the path '/mnt/media-library-ro/Video/Movies - Rifftrax'.

2026-05-03 16:57:57.389 Error App: Error in validateChildren for 401908 /mnt/media-library-ro/Music
	System.IO.DirectoryNotFoundException: System.IO.DirectoryNotFoundException: Could not find a part of the path '/mnt/media-library-ro/Music'.

2026-05-03 16:57:57.503 Error App: Error in validateChildren for 22736 /mnt/media-library-ro/Video/Series
	System.IO.DirectoryNotFoundException: System.IO.DirectoryNotFoundException: Could not find a part of the path '/mnt/media-library-ro/Video/Series'.

2026-05-03 16:57:57.503 Error App: Error in validateChildren for 674872 /mnt/media-library-ro/Video/Series Extras
	System.IO.DirectoryNotFoundException: System.IO.DirectoryNotFoundException: Could not find a part of the path '/mnt/media-library-ro/Video/Series Extras'.

2026-05-03 16:57:57.504 Error App: Error in validateChildren for 704468 /mnt/media-library-ro/Video/Theater & Opera
	System.IO.DirectoryNotFoundException: System.IO.DirectoryNotFoundException: Could not find a part of the path '/mnt/media-library-ro/Video/Theater & Opera'.

 

Edited May 12 by sa2000

[Luke 42528]

@gu5gushas this helped?

[gu5gus 1]

Hey sorry about the delay @sa2000 life got crazy there for a bit. 

Attached are "Info" level logs with the following playbacks from the library "Movies". I played each of the following for 10 seconds, all of which had artwork before and now do not:
Long Shot
Easy A
Bugonia
The Hound of the Baskervilles
Good Boy
Fear Street: 1666
A Different Man - this one had an unexpected playback error
Fear Street: 1978
Fear Street: Prom Queen
Fear Street: 1994

If you need more I can play more.

log set 2.zip

Edited May 21 by gu5gus

[sa2000 774]

8 hours ago, gu5gus said:

Attached are "Info" level logs with the following playbacks from the library "Movies". I played each of the following for 10 seconds, all of which had artwork before and now do not:
Long Shot
Easy A
Bugonia
The Hound of the Baskervilles
Good Boy
Fear Street: 1666
A Different Man - this one had an unexpected playback error
Fear Street: 1978
Fear Street: Prom Queen
Fear Street: 1994

Thanks for the logs and the info

I cannot see any attempts from Emby Web running in Firefox to request any images for the above - other than chapter images requested when playback was done

Were you viewing the media in the Movies Library ?  Latest Media view ?

Are you able to reproduce the library - perhaps in a test library ? where you have some movies with images and then you dismount the media mount and run some scans and bring it back again and have the images lost ? and remain to be lost after a rescan ?

If you can reproduce then the emby server logs (all of them embyserver.txt and earlier embyserver-xxxx.txt files) for whole period from launch of emby server until when the issue arises would hopefully have clues as to what happened. With Debug Logging enabled for whole period.

When providing logs it would be useful to know what time the screen was loaded that showed no images and which screen it was and perhaps a screenshpt

 

 

Edited May 21 by sa2000

[gu5gus 1]

I should add that I also discovered that some of the remaining collections that did not disappear have had some of their collection entries removed. More and more this looks like a database problem.

What I did was I loaded the library view, listed by Date Added, then played from there. I did not enter into each library entry's page to play it there. So the only time it would have tried to retrieve images was during the initial browsing into the library view. So I see my error there and I'll do it again this time clicking into each library entry's page to force it to try to fetch the artwork for each one.

Thank you for the instructions I will do this new stuff as soon as I can.

Edited May 21 by gu5gus

[sa2000 774]

it would be good if you are able to reproduce the problem by follwing specific steps rather than looking at the aftermath of loss of images

I presume the images would come back if you refresh metadata

[gu5gus 1]

Hello, here's an update:

1. I created a library "Movies2 TEST" using the same files as the "Movies" library which is affected by the missing artwork issue. Within 20 minutes after the initial library scan, the "Movies2 TEST" library appears to have exactly the same missing artwork as the "Movies" library. Perhaps this is to be expected since it would make sense that the files would have UUIDs and the artwork would be linked to that UUID, and the same files present in multiple libraries would have the same UUID in the database resulting in the same missing artwork. Therefore this may prove that this is a database issue.
 

2. Attached are another set of logs, this is for server version 4.9.3.0, and the client I used was the web client. This time it is "Debug Information" log level and here are the steps I followed to play each one:

1. Entered the library's webpage by clicking on it in the web interface.
2. Click on the title of the movie, bringing me to that movie's webpage.
3. Click to play from beginning. Let play for 10-40 seconds.
4. Click back to return to to the library's webpage.
5. Repeat steps 2-4 for each movie played.

And these are the movies that I played, all of them had artwork and some also had the actor art missing:

(starting here, these may have had their artwork cached by the web client:)
Easy A
Bugonia
The Hound of the Baskervilles
Good Boy
Fear Street: 1666
A Different Man - this one had a playback error
Companion
The Zone of Interest
Fear Street: 1978
Fear Street: Prom Queen
Fear Street: 1994
Send Help
(starting here, I dug deeper into the library to get stuff that hasn't been accessed in a very long time (probably never) so it shouldn't be cached:)
2010 The Year We Made Contact
Abbott And Costello Meet Dr Jeckyl and Mr Hyde
About Unknown Chaplin - this one had a playback error
Alaska, Silence and Solitude 
Alice in Acidland
Am Abend Nach Der Oper
An American Tale
And God Created The Woman
 

3. I have seen several times that refreshing metadata and choosing to replace images results in the artwork being restored.

4. I have not been able to reproduce the conditions where the metadata share was unmounted and that resulted in loss of artwork. As I had mentioned before, I have had the metadata share unmounted without resulting in loss of artwork approximately about one hundred times and this loss of artwork happened just once. However I do think I may have found a difference between the 100 times and the 1 time: the 100 times the metadata was unmounted before Emby server started up (except for 2-3 times where it unmounted while Emby was running), while the 1 time it unmounted while Emby was running (the server went down). My hypothesis is that the 1 time that resulted in artwork loss was because the database was corrupted during some write activity to most of the database entries, perhaps because it occurred at a critical moment during a library scan. Is there such a mass write action in the database ever? I don't know. But these things appear to suggest a database issue (corruption or otherwise):

1. Some collections have disappeared
2. Particular entries of some collections have disappeared
3. Both "Movies" and "Movies 2TEST" have the same artwork missing for the same movie file

 

log set 3.zip

Edited May 22 by gu5gus

[Luke 42528]

3 hours ago, gu5gus said:

Hello, here's an update:

1. I created a library "Movies2 TEST" using the same files as the "Movies" library which is affected by the missing artwork issue. Within 20 minutes after the initial library scan, the "Movies2 TEST" library appears to have exactly the same missing artwork as the "Movies" library. Perhaps this is to be expected since it would make sense that the files would have UUIDs and the artwork would be linked to that UUID, and the same files present in multiple libraries would have the same UUID in the database resulting in the same missing artwork. Therefore this may prove that this is a database issue.
 

2. Attached are another set of logs, this is for server version 4.9.3.0, and the client I used was the web client. This time it is "Debug Information" log level and here are the steps I followed to play each one:

1. Entered the library's webpage by clicking on it in the web interface.
2. Click on the title of the movie, bringing me to that movie's webpage.
3. Click to play from beginning. Let play for 10-40 seconds.
4. Click back to return to to the library's webpage.
5. Repeat steps 2-4 for each movie played.

And these are the movies that I played, all of them had artwork and some also had the actor art missing:

(starting here, these may have had their artwork cached by the web client:)
Easy A
Bugonia
The Hound of the Baskervilles
Good Boy
Fear Street: 1666
A Different Man - this one had a playback error
Companion
The Zone of Interest
Fear Street: 1978
Fear Street: Prom Queen
Fear Street: 1994
Send Help
(starting here, I dug deeper into the library to get stuff that hasn't been accessed in a very long time (probably never) so it shouldn't be cached:)
2010 The Year We Made Contact
Abbott And Costello Meet Dr Jeckyl and Mr Hyde
About Unknown Chaplin - this one had a playback error
Alaska, Silence and Solitude 
Alice in Acidland
Am Abend Nach Der Oper
An American Tale
And God Created The Woman
 

3. I have seen several times that refreshing metadata and choosing to replace images results in the artwork being restored.

4. I have not been able to reproduce the conditions where the metadata share was unmounted and that resulted in loss of artwork. As I had mentioned before, I have had the metadata share unmounted without resulting in loss of artwork approximately about one hundred times and this loss of artwork happened just once. However I do think I may have found a difference between the 100 times and the 1 time: the 100 times the metadata was unmounted before Emby server started up (except for 2-3 times where it unmounted while Emby was running), while the 1 time it unmounted while Emby was running (the server went down). My hypothesis is that the 1 time that resulted in artwork loss was because the database was corrupted during some write activity to most of the database entries, perhaps because it occurred at a critical moment during a library scan. Is there such a mass write action in the database ever? I don't know. But these things appear to suggest a database issue (corruption or otherwise):

1. Some collections have disappeared
2. Particular entries of some collections have disappeared
3. Both "Movies" and "Movies 2TEST" have the same artwork missing for the same movie file

 

log set 3.zip 8.68 MB · 0 downloads

Hi, if it were looking to have a standalone test, then try a new library with new folders that are not already imported into your Emby server.

[gu5gus 1]

I'm interested to see what @sa2000finds in log set 3 and now also in log set 4 (attached to this post). 

I however found something unexpected.

I have been thinking of a recovery from this situation, so I can suggest to your team a special button that can help those of us who have spent 200+ hours manicuring our large libraries recover from this without having to blow away our library and recreate it, losing all of our custom metadata. So I started methodically refreshing metadata artwork to see if this would recover from the original issue. I got about 3500 items into the library and stopped to wait for the system to catch up downloading artwork.  

Previously I thought it was successfully redownloading artwork for all entries, but this was just based on less than 10 instances where I tried it and it worked. Having now tried about 3000, I can see that plenty of them are refusing to download. I am fully certain that 100% of the ones that are refusing to download now had artwork downloaded successfully before the original issue began. I did a partial count and 593 of 3555 were missing artwork but had their artwork before the original issue happened. What's interesting is that they appear to have had the actor artwork successfully downloaded. I know this because many of the ones I checked have unique actors in them that aren't anywhere else in my library, and my checks before redownloading artwork always had the actor artwork missing. Attached are the logs from my manual attempt to redownload the missing artwork in the "Movies" library for around 3000 movies, it also should contain routine library scans since it covers about 1.5 days.

I did a check to see if the same was present in "Movies 2TEST" library and it was the same there based on spot checks.


I noticed something else. Ordering the "Movies" library by Title (alphabetical) resulted twice in groups of movies being listed out of order. It seemed that the groups listed out of order were the media contained in the "Christmas TV Specials & TV Episodes" folder, which I had been viewing in Library > Folders view just before. I have been using Emby several times a week every week for the past 9 years and I have never seen this happen before.

 

So, how can someone recover from my original issue of artwork going missing permanently when it happens? I had the following thoughts:

• Add a feature to be able to export and import a monolithic zip export of the custom metadata. This would possibly allow people with database issues or whatever this is to carry over their custom metadata from the old library to a new library. Custom metadata is just text so this should result in reasonable file sizes. Perhaps set a limit to the zip size to 100 MB and split it up in that fashion for very large libraries with very many customizations. I understand that the import to a new library would involve quite a bit of new code, but I don't see an alternative really since I don't think the next suggestion will address the issue (because no one fully understands it).
• Add some sort of database integrity check that can be manually executed. The check would verify all paths and remove anything that's invalid. Or whatever else is appropriate for this issue that no one seems to understand at the database level. This would require someone to dig around in my database, which I am happy to provide if you provide the instructions to retrieve it.
• Even better, create a button that creates a new library with the same path, creates the appropriate copies of the custom metadata, initiates the scan of the new library, and trashes the old library. Honestly I would prefer the export and import custom metadata feature since that means I could also create backups. 

I think we are probably near the end of my usefulness in this matter. But I'll continue to update if I see anything. 

log set 4.zip

Edited May 26 by gu5gus

[sa2000 774]

On 22/05/2026 at 21:41, gu5gus said:

1. I created a library "Movies2 TEST" using the same files as the "Movies" library which is affected by the missing artwork issue. Within 20 minutes after the initial library scan, the "Movies2 TEST" library appears to have exactly the same missing artwork as the "Movies" library.

This is not a valid test. You have both libraries pointing to the same media folder

Library:  Movies2 TEST
Configured paths: /mnt/media-library-ro/Video/Movies

Library:  Movies
Configured paths: /mnt/media-library-ro/Video/Movies

The movie item in the database will be the same row in the database and so the outcome will be the same

You could create a new folder, e.g. 

/mnt/media-library-ro/Video/Movies-Test3

and copy into that folder a couple of movies eg Bugonia which you have an issue with and another movie that you do not have an issue with. Then create a new library with this Movies-Test3 folder path

and at the end of the scan and the composite library movies image showing, then do a test of opening this new library and viewing the two movies - noting down the time and names of the movies and if there are images or not, then after that:  viewing the same movies in the old library and noting down the times and getting the debug embyserver log for the tests

At this point, you could also let me have a zip of the library.db file - copied out when the server is shutdown - path being: /var/lib/emby/data/library.db

(I will send you a link for upload)

 

Other feedback to you - unrelated

* You have issues with some music metadata - where instead of there being a MusicBrainz ID, you actually have the text string:  "usicBrainz"  -  Have a look at metadata for music for "James Brown" /  example: Funky Christmas. This is just an example

* You have a library "Series Extras & Featurettes" - The path for it does not exist/ cannot be found/reached

/mnt/media-library-ro/Video/Series Extras

* Suspected issue with this subtitle file giving an ffmpeg error

/mnt/media-library-ro/Video/Movies/Fear Street Prom Queen (2025) 1080p x265.srt

* configuration issue with OpenSubtitles

2026-05-24 23:00:21.673 Info OpenSubtitles: Logging into OpenSubtitles-Emby
2026-05-24 23:00:21.674 Error SubtitleManager: Error searching for subtitles on Open Subtitles

authentication failed. Please reconfigure your Open Subtitles username and password

 

Edited Monday at 02:39 PM by sa2000