There are no issues as such yet.
But just an obligatory post for potential updates needed for the InfuseSync plugin for the upcoming Jellyfin v12.0 release, given they have v2 release candidate out as of yesterday (28 Jun 2026).
Happy to test things out as well if needed.
We’re doing some internal testing with 12.0, but if anyone comes across issues or quirks feel free to share them here.
InfuseSync appears to be incompatible with Jellyfin 12.
GET /InfuseSync/Checkpoint/{checkpointID}/UpdatedItems fails with:
System.MissingMethodException: IDtoService.GetBaseItemDtos(...)
Jellyfin 12 changed GetBaseItemDtos from 4 to 5 parameters by adding bool skipVisibilityCheck = false in commit 5996c4a.
InfuseSync seems to still be compiled against the old 4-parameter signature. Rebuilding against the Jellyfin 12 assemblies / updating the method call should fix this specific error.
In progress. 
InfuseSync 1.5.3 is now available for Emby (4.9+) and Jellyfin (12.0+). 
What’s new in v1.5.3:
Installing and updating can be done through the normal channels.
Note: A server restart will be required when installing/updating plugins.