// HACKER NEWS — CYBERSECURITY
Jellyfin 12.0
We are pleased to bring you Jellyfin 12.0, our new stable release. This release continues in the same direction as 10.11: finishing what the database conversion started, turning that new foundation into real performance work, and finally giving books and comics the support they have deserved for years.
If you just want a quick summary of what you need to know to get your system upgraded and running, please read on to the "TL; DR" section just below, or keep reading for a full explanation of all the major features and improvements in Jellyfin 12.0! You can also view full changelogs on the server and web GitHub releases.
IT IS VERY IMPORTANT THAT YOU READ THIS SECTION BEFORE UPGRADING TO JELLYFIN 12.0! Failure to do so may cause issues! Always feel free to ask for help in our chat if you are unclear or run into trouble.
This release changes the database schema and actively rewrites data on first boot, so a backup is the only way back to your previous version.
As always for major upgrades, ensure you STOP Jellyfin and take a FULL MANUAL BACKUP OF YOUR DATA AND CONFIG DIRECTORIES before upgrading!
You must be running Jellyfin 10.10.7 or any 10.11.x release before upgrading to 12.0. Upgrading directly from 10.11.x is fully supported and no intermediate step is needed. If you are on anything older than 10.10.7, upgrade to 10.10.7 first, then upgrade to 12.0.
Check your usernames before upgrading. Usernames are now case insensitive, so two accounts can't have names that only differ by capitalization. If you have users that match this pattern the database migration will fail.
A full library scan is REQUIRED after upgrading. As part of fixing how alternate versions are stored, versions that Jellyfin grouped automatically, not ones you merged yourself, are cleared during the upgrade. Until you run the scan those versions will look like they are missing.
The first scan after upgrading will take significantly longer than normal, and some movies may appear as newly added. This is expected. Jellyfin now checks every item in your library against the files on disk to clear out leftovers from previous versions, and anything that was previously filed incorrectly gets corrected as it goes. Do not stop the server while migrations are running.
Once installed, please ensure you hard refresh (e.g. Ctrl+Shift+R or similar) and/or clear your web cache for your Jellyfin instance if you notice any UX anomalies. Bad cached assets are the #1 cause of such issues.