4.9.x – Collections appear missing while artwork/metadata repopulates after refresh

[josenightbreed 5]

Emby 4.9.x – Collections temporarily missing / missing artwork after library refresh, eventually repopulate after forced image refresh

I wanted to document an issue I ran into with Collections on Emby 4.9.x in case it helps anyone else or provides useful information for the developers.

Server

• Emby Server 4.9.x

• Native Linux installation

• Linux Mint

• Large movie library (2,000+ movies)

• Automatic collections enabled

• Minimum automatic collection size: 2 movies

• TheMovieDb enabled

• A small number of additional dynamic/curated collections managed by the ACdb.tv plugin

Symptoms

I initially noticed that a large number of collection posters were missing.

The collections themselves were visible, but many had blank artwork.

Refreshing an individual collection using:

Collections → Collection → Refresh Metadata

with:

• Replace images: Enabled

• Video preview replacement was also enabled during the first test

caused the collection image to appear correctly.

I then selected the collections in bulk and ran the same metadata refresh with Replace images enabled.

This successfully restored the collection artwork.

However, shortly afterward I noticed what appeared to be a second problem: the number of visible collections seemed much lower than expected.

I remembered having roughly 350 collections, but at one point only around 140 appeared to be visible.

For example:

30 Days of Night Collection

was not visible even though both:

• 30 Days of Night (2007)

• 30 Days of Night: Dark Days (2010)

were present in the library.

Refreshing those two movies did not immediately recreate or reveal the collection.

Database investigation

Before modifying anything, I checked library.db.

The supposedly missing collection was still present:

Id      type  Name                         Path  ParentId  ProviderIds
------  ----  ---------------------------  ----  --------  -----------
218205  9     30 Days of Night Collection                  Tmdb=91660

The movie-to-collection links were also intact:

LinkType  ItemId  ItemName                     LinkedId  LinkedName
--------  ------  ---------------------------  --------  ---------------------------
6         134238  30 Days of Night             218205    30 Days of Night Collection
6         134242  30 Days of Night: Dark Days  218205    30 Days of Night Collection

Both movies also still had their imported collection information:

ItemId  Name                         ProviderIds
------  ---------------------------  -----------
134238  30 Days of Night Collection  Tmdb=91660
134242  30 Days of Night Collection  Tmdb=91660

The collection count in the database eventually showed:

CollectionsInDatabase
---------------------
333

So the collection records had apparently not actually been lost.

TMDb activity

The Emby log showed the server actively requesting collection metadata/images from TMDb and receiving HTTP 200 responses.

Example, with the API key removed:

Info HttpClient: GET https://api.themoviedb.org/3/collection/9380?api_key=[REDACTED]&append_to_response=images&language=en-US&include_image_language=en-US,null
Info HttpClient: Http response 200 from https://api.themoviedb.org/3/collection/9380?... after 46ms

Info HttpClient: GET https://api.themoviedb.org/3/collection/98036?api_key=[REDACTED]&append_to_response=images&language=en-US&include_image_language=en-US,null
Info HttpClient: Http response 200 from https://api.themoviedb.org/3/collection/98036?... after 50ms

There were many requests like this occurring one after another.

What ultimately happened

After the bulk collection refresh with Replace images enabled, the collections and their artwork began appearing gradually.

Refreshing the Collections page periodically showed more and more collections.

Eventually the visible number rose to approximately the same number of collection objects present in the database.

The ACdb-managed collections also began appearing normally again without changing the ACdb configuration.

Working procedure

What worked for me was:

• Open Collections from the normal Emby user interface.

• Select the affected collections, or bulk-select all collections.

• Choose Refresh Metadata.

• Enable Replace images.

• Start the refresh.

• Allow Emby to continue processing.

• Do not immediately assume missing collections have been deleted.

• Refresh the Collections page periodically and allow time for the entries/images to repopulate.

In my case, collections appeared gradually while Emby continued downloading collection metadata and artwork.

Possible 4.9.x issue

What was confusing is that the UI initially made it look as though a large portion of the collections had disappeared, even though:

• The collection objects still existed in MediaItems

• Their TMDb IDs were still present

• Movie-to-collection links in ItemLinks2 were intact

• ImportedCollections still contained the correct collection information

• TMDb requests were succeeding with HTTP 200 responses

This makes me wonder whether there is an issue in 4.9.x involving collection metadata/image refreshes, cache invalidation, asynchronous collection rebuilding, or how the Collections view is updated while a large refresh is still running.

It may also be useful if the UI could indicate that collection metadata/artwork is still being processed, because during a large refresh it can look as though collections have actually been removed.

No direct database modifications were required to resolve the issue.

Hopefully this information and the database/log details are useful for tracking down any remaining Collections-related issues in the 4.9.x releases.

 

I hope this helps somehow; I've had this issue multiple times during the 4.9.x versions; I just had not been able to do anything with it for health issues. I will also add that the investigation and troubleshooting were with ChatGPT's aid. Got to put it to work in something useful and not just make cat girl pics and videos lol.

embyserver.txt

[Luke 42963]

Hi, are you able to get the issue to happen again?

[josenightbreed 5]

i will try, but it might take a very long time because of the size of my anime, movies, shows, and music. I will have to delete the database and recreate it like a fresh install to see if it happens again.

[Luke 42963]

OK I wouldn't do that. You're saying this was a one-time problem then?

[josenightbreed 5]

No, it has happened before in the 4.x versions, when I have had to recreate the database because of different reasons, like a disk that failed and once a bad kernel I was experimenting with updating in the server pc, plus there are other services running on that same machine.

Edited 33 minutes ago by josenightbreed

[Luke 42963]

I think this is already resolved in the upcoming 4.10 server release so just fyi, I don't think you need to spin your wheels on it.

[josenightbreed 5]

awesome!!
If you need or want logs and stuff from the media server pc, let me know and i will provide them