Upgraded to Unity 6: Prefabs containing Lights have the wrong Light Type until I manually edit/save prefab

Unity Engine
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I’m upgrading my project from 2021.3 to Unity 6, so it’s possible this is the result of an earlier version’s changes. I don’t see anything in the HDRP version upgrade notes about this, though.

What I’m seeing is that my prefabs that contain lights have an incorrect Light Type until I manually open the prefab and save it.

Here’s an example of a prefab instance in a scene, containing a point light:

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Now I open the prefab and look at it, and it looks the way it’s supposed (500 Lumens is what it was set to in 2021.3):

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It’s worth mentioning that the incorrect display showing Candela is not showing up as a property edit to the prefab. Unity is showing the wrong value there, but it thinks it’s showing the correct value.

I can “fix” this as long as I make any change to the prefab asset, such that it causes the prefab to be saved. I don’t need to change any of the properties of the light. Once I make any change, I can see in version control that a whole bunch of changes have been made to the prefab asset. After saving the prefab asset, if I look at the prefab instance in the scene again, it’s displaying properly, showing “500 Lumen”.

Is this a bug, or an expected outcome of migrating a project to Unity 6? I don’t see any HDRP tools, like the material upgrader, to fix the lights on prefabs. Does one exist? Should one exist? Is there a way I can easily correct this, other than opening every prefab asset in my project and saving it?

Thanks.

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I have a similar issue with Unity 6: I started a new project, created a basic 2d rectangle with shadow caster, confirmed it is casting a shadow from a basic spotlight and then made a prefab of it. All manually created or in-game spawned objects from that prefab do not cast shadows. I got a shadow to work by changing an attribute manually in the inspector. I downgraded the project to 2022.3.55f1 and with zero changes to the project, the prefabs are casting shadows just fine.