Create Error: Object Duplication

Hello, I opened the demo marbles scene in Create and save only the marbles to their own USD file.
When I import those marbles into a new empty scene (drag and drop from Content browser), and then attempt to Duplicate a marble (crtl+D), nothing happens.

I notice that the console gives me the following error:

2021-07-27 22:35:05  [Error] [carb.python] Failed to execute a command: CopyPrim.
  File "c:\users\<USERNAME>\appdata\local\ov\pkg\create-2021.3.1\kit\extscore\\omni\kit\menu\utils\scripts\", line 153, in on_input
  File "c:\users\<USERNAME>\appdata\local\ov\pkg\create-2021.3.1\kit\exts\\omni\kit\menu\edit\scripts\", line 261, in <lambda>
    onclick_fn=lambda: EditMenuExtension.duplicate_prim(False, False),
  File "c:\users\<USERNAME>\appdata\local\ov\pkg\create-2021.3.1\kit\exts\\omni\kit\menu\edit\scripts\", line 458, in duplicate_prim
    "CopyPrims", paths_from=copy_paths, duplicate_layers=duplicate_layers, combine_layers=combine_layers
  File "c:\users\<USERNAME>\appdata\local\ov\pkg\create-2021.3.1\kit\extscore\omni.kit.commands\omni\kit\commands\", line 228, in execute
    return omni.kit.undo.execute(command, name, kwargs)
  File "c:\users\<USERNAME>\appdata\local\ov\pkg\create-2021.3.1\kit\extscore\omni.kit.commands\omni\kit\undo\", line 72, in execute
    result = _execute(command, name, level, history_key)
  File "c:\users\<USERNAME>\appdata\local\ov\pkg\create-2021.3.1\kit\extscore\omni.kit.commands\omni\kit\undo\", line 279, in _execute
    result =
  File "c:\users\<USERNAME>\appdata\local\ov\pkg\create-2021.3.1\kit\extscore\omni.usd\omni\usd\commands\", line 400, in do
  File "c:\users\<USERNAME>\appdata\local\ov\pkg\create-2021.3.1\kit\extscore\omni.kit.commands\omni\kit\commands\", line 228, in execute
    return omni.kit.undo.execute(command, name, kwargs)
  File "c:\users\<USERNAME>\appdata\local\ov\pkg\create-2021.3.1\kit\extscore\omni.kit.commands\omni\kit\undo\", line 72, in execute
    result = _execute(command, name, level, history_key)
  File "c:\users\<USERNAME>\appdata\local\ov\pkg\create-2021.3.1\kit\extscore\omni.kit.commands\omni\kit\undo\", line 312, in _execute
    raise e
  File "c:\users\<USERNAME>\appdata\local\ov\pkg\create-2021.3.1\kit\extscore\omni.kit.commands\omni\kit\undo\", line 279, in _execute
    result =
  File "c:\users\<USERNAME>\appdata\local\ov\pkg\create-2021.3.1\kit\extscore\omni.usd\omni\usd\commands\", line 346, in do
    Sdf.CopySpec(layer, self._path_from, dst_layer, self._path_to)

 <class 'pxr.Tf.ErrorException'> 
	Error in 'pxrInternal_v0_20__pxrReserved__::SdfCopySpec' at line 573 in file E:\w\ca6c508eae419cf8\USD\pxr\usd\sdf\copyUtils.cpp : 'Cannot copy unknown spec at </World/___SOLO_Marbles/Marbles/A_marble_01> from layer <omniverse://localhost/Projects/Marbles/Parts/SOLO_Marbles.usd>'

hello @jasonadorris -
what version of Create are you using?

Create 2021.3.1
OS: Windows 10 | GPU: RTX 3070Ti | RAM: 64 GB | CPU: Intel i9-10980XE

hello @jasonadorris -
Is it possible to attach a few of those saved marbles for repo?

hello @jasonadorris -
Can you also attach your Create logs. Zip up all contents. Do this after you repro the issue in create

hello @jasonadorris -
Can you review this video. Think i might have reproduced your issue. The video shows how one might workaround this issue, Please tell me your results.

Please take a look at the files available here:

I have included the USD, logs, and a video showing how to reproduce.

1.] Open the full marbles demo scene
2.] Delete everything except the marbles
3.] Save the file as it’s own USD
4.] Create a new scene
5.] Import the new marbles USD
6.] Duplicate a marble (by any means)

I have also been seeing lots of random crashes. I captured one while making that last video (logs included). Might be related?

hello @jasonadorris
I have been able to reproduce your issue. Development is working on solution. Will post back when available. But in until then i might have a workaround.

What i did was export each of the marbles as a unique .usd (not as a single usd with N marbles). Then i can place into a stage individually. At this point to duplicate, need to use the stage later (highlight item, like M0) then do the duplicate operations. Can you try this?

Attached are the marbles that i created M0…M10
Marbles (479.4 KB)

Note: I see the crash also. Looking into that issue too


Thanks for your help, but I am facing an even more dire issue at the moment. The USD scene I had been using for my contest entry (due tomorrow) has now gone missing after a reboot. I had noticed that I was getting some new and different error messages after trying to duplicate a marble (was working earlier). This new error says:

2021-07-29 18:55:05 [67,093ms] [Warning] [omni.client.plugin]  Main: usd_plugin: Could not open asset @omniverse://localhost/Projects/Marbles_machines_6_30_21b/assets/A_marble.usd@ for reference on prim @omniverse://localhost/Projects/Marbles/Parts/Top_Distro.usd@,@anon:000001AE35EECCA0@</Marbles_COLORED_01__01/A_marble_01>. (recomposing stage on stage @omniverse://localhost/Projects/Marbles/Parts/Top_Distro.usd@ <000001B5DA762060>)
2021-07-29 18:55:05 [67,093ms] [Warning] [omni.usd] Warning: in _ReportErrors at line 2830 of E:\w\ca6c508eae419cf8\USD\pxr\usd\usd\stage.cpp -- Could not open asset @omniverse://localhost/Projects/Marbles_machines_6_30_21b/assets/A_marble.usd@ for reference on prim @omniverse://localhost/Projects/Marbles/Parts/Top_Distro.usd@,@anon:000001AE35EECCA0@</Marbles_COLORED_01__01/A_marble_01>. (recomposing stage on stage @omniverse://localhost/Projects/Marbles/Parts/Top_Distro.usd@ <000001B5DA762060>)

I thought this was weird so I saved and closed Create, rebooted my computer, and when I re-opened Create, and tell my scene to open (from “Open Recent”) and get an error saying the file cannot be found. I notice my USD scene file was missing from the Create Content browser, as well as from Nucleus. (logs attached)

I read that Nucleus is supposed to keep version control, but all I can find in the docs is the checkpoints within a USD file, nothing for files that go missing.

Am I boned here? Is there any way to get this file back? (159.9 KB)

The workstation Nucleus does not provide automatic backups. The checkpointing allow one to have history of diff versions of the asset over time.

But sounds like the entire asset is gone. (thus checkpointing is not relevent)

  1. Are there any folders or files present where you had the scene?
  2. Assume you stopped/started Create and still nothing in the content browser.

The log files sent are for Create. The problem might be in Nucleus
Can you zip up everything in this folder


I can look at the logs, but at the moment don’t have a solution to get back missing data from Nucleus.

1.] yes, all adjacent folders / files are still available, as well as all source USDs referenced in my scene
2.] yes, re-launched app and rebooted computer. File is still missing.

Nucleus logs attached: (3.7 MB)

What was the name of the missing file?
and path


I usually save scene files incrementally as I progress, for redundant backups. I think reading about the Nucleus version control gave me a false sense of security.

It was a major bummer to lose a week’s worth of work to a bug like this. I felt that I had a strong submission for the contest and there is no way to start over and complete in time.

Along with the marble contest deadline, my interest in this Omniverse has also expired. I see a lot of potential here, I’ll check in in a few years when it’s more stable.

Best of luck!