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Fixed in 2020.1.X

Fixed in 2019.3.X



Found in




Issue ID




[SerializeReference] Assets lose its Data when a Class name is changed



To reproduce:

1. Download attached "" project and open in Unity
2. Select "New Some Thing" gameObject in the Project window
3. Click from the main menu BugReport > Populate Selected Some Thing
4. While "New Some Thing" gameObject is selected in Inspector expand "Element 0" and notice it has a "Left" and "Right" item
5. Open Scripts/SomeThing.cs script
6. Rename the class "RootNode" to "RootNodeNewName" and save it
7. Switch back to Unity Editor

Expected results: Renaming class names should not cause Fata loss
Actual results: Observe that the Data is gone. "Element 0" no longer shows a "Left" and "Right" item and Console outputs Error:

"Unknown managed type referenced: [Assembly-CSharp] .RootNode"

- This issue appears on both Windows and macOS
- Could not check on Unity 2019.3.0a1 because the project becomes corrupted
- Customer copied the example snippet for the new [SerializeReference] feature from
- Another Forum link:

Reproduced on Unity 2019.3.0a2, 2019.3.0b3 and 2020.1.0a1

Comments (8)

  1. BayernMaik

    Nov 19, 2021 17:53

    Still broken in 2021_2_2f1

  2. sRioni

    Apr 28, 2021 23:20

    It also happens in 2020.3.3f1 :(

  3. the_Whizzkid

    Jan 16, 2021 14:32

    2019.4.17f1: Issue happens, too. with class: MyLocaleSelector

  4. hugeandy

    Nov 19, 2020 14:04

    Seeing this in 2020.1.11f1 when changing namespaces of ScriptableObjects.

    I created a ScriptableObject asset, which has a [SerializeReference] List<T> where T is a [Serializable] public non-abstract class. I added a few items to the list. I then changed the namespace of some of the T classes.

    Now, when I click on the asset in the Project view, Unity takes around 15s to update before I can edit it, and spits out some of the "Unknown managed type referenced" errors.

    I notice that I change this asset in the inspector and then save/close unity, the asset file on disk does not update.

  5. webbertakken

    May 25, 2020 18:24

    Happens on 2019.3.8f1 too

  6. KMacro

    Feb 26, 2020 00:33

    I am still seeing this issue in 2019.3.2f1 and 2020.1.0a24.

    This behavior also occurs when the class is removed entirely from the assembly.

    A huge consequence of this is that any collection containing an object that references the changed/deleted class will have all of its entries nullified, regardless of if they themselves have a reference to the class.

    I have reported my specific problems in ticket #1218905.

  7. kvfreedom

    Dec 05, 2019 08:05

    Should be fixed in 2019.4

  8. kyuskoj

    Nov 27, 2019 19:33

    fixed in 2020 only? what about 2019.3

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