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Fixed in 2021.2.X

Fixed in 2020.3.X, 2021.1.X



Found in




Issue ID




Crash on Transform::CountNodesDeep when calling InstantiatePrefab and passing a Transform received from the Prefabs Component

Scene Management


How to reproduce:
1. Open the attached project (
2. In the Project window select the 'Prefab' Asset
3. At the top of the Editor click 'Examples' -> 'Case 1276785'

Reproducible with: 2018.4.27f1, 2019.4.10f1, 2020.1.5f1, 2020.2.0b3, 2021.1.0a1

First lines of the stacktrace:
0x00007FF73F4C43B7 (Unity) Transform::CountNodesDeep
0x00007FF73F4CA7DB (Unity) Transform::RebuildTransformHierarchy
0x00007FF73E34750B (Unity) SynchronizeMeshRenderersAndMaterials
0x00007FF73E34740A (Unity) AssetHotreload
0x00007FF740D61CFC (Unity) AssetHotreload
0x00007FF740DF346B (Unity) RefreshInternalV2

1. The error message 'Cyclic nesting detected' is logged right before the crash
2. Issue reproduces not only with Script Components
3. 'EditorUtility.SetDirty(prefab)' and 'AssetDatabase.SaveAssets()' have to called as well for the crash to occur

  1. Resolution Note (fix version 2021.2):

    Fixed in 2021.2.0a9

  2. Resolution Note (fix version 2021.1):

    Fixed in: 2021.1.0a2

  3. Resolution Note (fix version 2020.3):

    Fixed in: 2020.3.18f1

Comments (1)

  1. k1lly0u-chaos

    Oct 10, 2022 01:49

    This issue is still present in 2020.3.35f1, 2020.3.37f1 and 2020.3.40f1 (as far as I have tested)

    For me I enter then exit play mode, after which as soon as any code is changed and Unity recompiles the editor will crash every time.

    I downgraded to 2020.3.18f1 and the editor no longer crashes

    ========== OUTPUTTING STACK TRACE ==================

    0x00007FF7CB796137 (Unity) Transform::CountNodesDeep
    0x00007FF7CB79B48B (Unity) Transform::RebuildTransformHierarchy
    0x00007FF7CAD6A367 (Unity) SynchronizeMeshRenderersAndMaterials
    0x00007FF7CAD6A26A (Unity) AssetHotreload
    0x00007FF7CC8517D2 (Unity) AssetHotreload
    0x00007FF7CC8B8255 (Unity) RefreshInternalV2
    0x00007FF7CC8C1176 (Unity) StopAssetImportingV2
    0x00007FF7CC8B8F59 (Unity) RefreshV2
    0x00007FF7CC84C460 (Unity) AssetDatabase::Refresh
    0x00007FF7CC329BDA (Unity) Application::AutoRefresh
    0x00007FF7CC7D9AB0 (Unity) ContainerWindow::ContainerWndProc
    0x00007FFBBAC6E858 (USER32) CallWindowProcW
    0x00007FFBBAC6E3DC (USER32) DispatchMessageW
    0x00007FFBBAC80BC3 (USER32) SendMessageTimeoutW
    0x00007FFBBCB10E34 (ntdll) KiUserCallbackDispatcher
    0x00007FFBBA9C1064 (win32u) NtUserPeekMessage
    0x00007FFBBAC6A5C3 (USER32) PeekMessageW
    0x00007FFBBAC6A523 (USER32) PeekMessageW
    0x00007FF7CC7B0DFB (Unity) MainMessageLoop
    0x00007FF7CC7B53B1 (Unity) WinMain
    0x00007FF7CDE8326E (Unity) __scrt_common_main_seh
    0x00007FFBBB9A7034 (KERNEL32) BaseThreadInitThunk
    0x00007FFBBCAC26A1 (ntdll) RtlUserThreadStart

    ========== END OF STACKTRACE ===========

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