SOLVED: Collections show as empty, "Requested value 'SongCount' was not found."

[NaturalBornCamper]

Was the version of Jellyfin the same on both servers?  The path for all your media is in exactly the same path as the previous server?  When moving files from one machine to the next, the permissions might not transfer so double check permissions.

Old server = Jellyfin 10.8.13 on Linux (No Docker or complicated paths, simple install using DietPi)
New server = Jellyfin 10.8.13 on Windows Server 2022 (again no Docker shenanigans)

For the migration, I checked the existing migration script that goes from Windows to Linux, but it didn't work from Linux to Windows (buggy, issues with paths, etc) so I made my own in Python with all those replacements:

Code:

# library.db and text file replacements
('/data/media/movies', 'X:/Movies'),
('/data/media/series', 'Y:/Series'),
(r'\\192.168.0.52\movies\Movies', r'\\192.168.0.52\Movies\Movies'),
(r'\\192.168.0.52\tv\Series', r'\\192.168.0.52\tv\Series'),

# For the custom filters containing these
('/series/', '/Series/'),
# For the custom filters containing these
('/movies/', '/Movies/'),

# Seen those in files
('/mnt/dietpi_userdata/jellyfin/metadata', 'C:/ProgramData/Jellyfin/Server/metadata'),
("/etc/jellyfin", "C:/ProgramData/Jellyfin/Server/config"),
("/mnt/dietpi_userdata/jellyfin/cache", "C:/ProgramData/Jellyfin/Server/cache"),
("/var/log/jellyfin", "C:/ProgramData/Jellyfin/Server/log"),
("/mnt/dietpi_userdata/jellyfin", "C:/ProgramData/Jellyfin/Server"),
("/mnt/dietpi_userdata/jellyfin/transcodes", "C:/ProgramData/Jellyfin/Server/transcodes"),
("/usr/lib/jellyfin-ffmpeg/ffmpeg", "C:/Program Files/Jellyfin/Server/ffmpeg.exe"),
("/usr/share/jellyfin-ffmpeg", "C:/Program Files/Jellyfin/Server/ffmpeg.exe"),

The script checks every single database table, row, column and does the replacements, as well as every single file it manages to open as text without throwing an exception (so not only xml files, also mblink files, etc)

Everything worked perfectly, even the watched status and metadata was reused... until I noticed the empty collections a week later. Then I saw that I had not not seen this replacement:
/collections  -> \collections
So I checked the files and the DB, made the replacements, but still nothing so I don't get it.

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Feels like a version mismatch between the frontend and backend

How can you have a mistmatch between the Server and the Web? Don't they come packaged together as a single installation?

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Ok... I opened the web interface again to send a screenshot that I thought might be helping... and all the collections are back 0_o

I didn't do anything since yesterday so I'm extremely confused now. Maybe after I ran the replacements /collections -> \collections, there was a cache issue and it just needed to refresh. But no matter, not it seems it's fixed so I'm sorry for wasting everybody's time!