Known Issues


  1. Currently there is a 1 GB file size limit on individual USD files that can be loaded.

  2. Replicator Composer has a memory leak when generating data.

  3. When running samples from the standalone_examples via ./ they might not exit/shutdown cleanly:

    [Warning] [carb.tasking.plugin] Leaking 1 carb::tasking::Counter instances!
    Shutting Down Complete
    ./ line 27:  8164 Segmentation fault      (core dumped) $python_exe $@
    There was an error running python
  4. If running Omniverse Isaac Sim headless connected via the remote client and you exit on shutdown the following error can occur, it can be ignored:

    [ext: omni.physx] shutdown
    Fatal Python error: Segmentation fault
    Thread 0x00007f46f8faa740 (most recent call first):
    File "..._build/target-deps/kit_sdk_release/_build/linux-x86_64/release/extsPhysics/omni.physx/omni/physx/scripts/", line 30 in on_shutdown
    File "..._build/target-deps/kit_sdk_release/_build/linux-x86_64/release/plugins/bindings-python/omni/ext/impl/", line 225 in shutdown_all
    File "..._build/target-deps/kit_sdk_release/_build/linux-x86_64/release/plugins/bindings-python/omni/ext/impl/", line 261 in shutdown_all_extensions
    File "..._build/target-deps/kit_sdk_release/_build/linux-x86_64/release", line 3 in <module>
  5. When running in windowed container, the following errors may be ignored and the app will continue to run after waiting for awhile:

    ERROR: Could not find a version that satisfies the requirement psutil (from versions: none)
    ERROR: No matching distribution found for psutil
    WARNING: Retrying (Retry(total=4, connect=None, read=None, redirect=None, status=None)) after connection broken by 'NewConnectionError('<pip._vendor.urllib3.connection.VerifiedHTTPSConnection object at 0x7fcdcc284dd8>: Failed to establish a new connection: [Errno -3] Temporary failure in name resolution',)': /simple/psutil/``
  6. Enabling the ROS2 extension is not persistent across restarts of Isaac Sim

  7. If exiting standalone python scripts with Ctrl-C, it may need to be done twice to exit.

  8. If Nucleus is not working on Docker, see Manually Installing Nucleus in a Container

  9. If more than one asset in URDF contains the same material name, only one material will be created, regardless if the parameters in the material are different (e.g two meshes have materials with the name “material”, one is blue and the other is red. both meshes will be either red or blue.). This also applies for textured materials.

  10. When updating Isaac Sim assets from version 2021.2.0, the “Checking Nucleus for Isaac Sim Assets” dialog box will still pop-up after a completed download. A workaround is to delete the old 2021.2.0 file from the /Isaac folder or check Delete folder before download before starting the download.

  11. MJCF importer does not show the built-in bookmark in the file picker dialog. The bookmark is still available in the content pane and can be copy-pasted into the file picker dialog.

  12. If you see a black screen when running on Windows, use the --vulkan command-line argument during startup

  13. Debug Visualizations are not present in fisheye lens cameras that are not pinhole because that feature is not implemented.


  1. Warnings similar to the following can be ignored:

    • [Warning] [omni.usd] Warning (secondary thread)

    • [Warning] [carb.tasking.plugin] Counter 0x7f25e002f8d0

    • [Warning] [rtx.neuraylib.plugin] [MDLC:COMPILER]   1.0   MDLC   comp warn

    • [Warning] [rtx.mdltranslator.plugin] Unable to resolve

    • [Warning] [omni.tagging.plugin] Failed to discover tagging service

    • [Warning] [omni.isaac.dynamic_control.plugin] DcFindArticulationDof: Function called while not simulating

    • [Warning] [omni.isaac.dynamic_control.plugin] DcSetDofProperties: Function called while not simulating

    • [Warning] [omni.client.plugin]  Tick: authentication: Could not connect to discovery service at "wss://...

  2. If Physics is not needed this message can be ignored:

    • [Warning] [omni.physx.plugin] Physics USD: Physics scene not found. A temporary default PhysicsScene prim was added automatically!

  3. If there is unwanted noise in simulated depth images, disable anti-aliasing under the Render Settings ->Ray Tracing -> Anti-Aliasing tab by setting the Algorithm to None

  4. Pyperclip is used to copy text in some extensions, if you see the following message please refer to the link to install a supported copy/paste mechanism

    Pyperclip could not find a copy/paste mechanism for your system.
    For more information, please visit


  1. Errors similar to the following can be ignored:

    • [Error] [omni.client.plugin]  Main: usd_plugin: Type mismatch for <...>: expected 'SdfAssetPath', got 'GfVec3f'

    • [Error] [omni.client.plugin]  Main: usd_plugin: Failed verification:

    • [Error] [carb.python] omni.kit.window.file -> <class '...'>: extension object is still alive, something holds a reference on it...

    • [Error] [omni.physx.plugin] USD stage detach not called, holding a loose ptr to a stage!

  2. Errors similar to the following can be ignored when running headless:

    [Error] [carb.windowing-glfw.plugin] GLFW initialization failed.
    [Error] [carb] Failed to startup plugin carb.windowing-glfw.plugin (interfaces: [carb::windowing::IGLContext v1.0],[carb::windowing::IWindowing v1.2]) (impl: carb.windowing-glfw.plugin)
    [Error] [carb.scripting-python.plugin] RuntimeError: Failed to acquire interface: carb::windowing::IWindowing (pluginName: nullptr)
    /isaac-sim/kit/exts/omni.kit.window.cursor/omni/kit/window/cursor/ on_startup
    /isaac-sim/kit/plugins/bindings-python/omni/ext/impl/ _startup_ext
    /isaac-sim/kit/plugins/bindings-python/omni/ext/impl/ startup_all_extensions_in_module
    /isaac-sim/kit/plugins/bindings-python/omni/ext/impl/ startup_all_extensions_in_module
    PythonExtension.cpp::startup()(2): <module>
    [Error] [omni.ext.plugin] [ext: omni.kit.window.cursor-1.0.1] Failed to process python module extension in '/isaac-sim/kit/exts/omni.kit.window.cursor/.'.
  3. If you see the following, please make sure that python processes for any previously executed training runs are killed:

    • [Error] [carb.cudainterop.plugin] CUDA error 708: cudaErrorSetOnActiveProcess - cannot set while device is active in this process)

  4. These errors can be ignored while running the running Kit Remote Client, if the client works as normal:

    ERROR [BifrostClient: Streamer] {2B436200} -  updateVideoSettingsForNVbProfile: profile 8 is not handled
    ERROR [NVST:ClientSession] {1E8D2700} -  Number of channels(2) is not valid for surround configuration
    ERROR [NVST:ClientSession] {1E8D2700} -  Either in stereo or error in receiving opus information from server
    ERROR [LAVCDecoder] {FC4A0700} - GERONIMO_ERROR 0xC0040006 GERONIMO_LAVCDECODER_DECODE: Packet decode failure.
    ERROR [NVST:ClientLibraryWrapper] {1E8D2700} -  Cannot find streamEventRaised for type 1
    ERROR [NVST:ClientLibraryWrapper] {1E8D2700} -  Cannot find streamEventRaised for type 2
    ERROR [NVST:RtspSessionPocoBase] {FB280700} -  perform() failed: 0
    ERROR [NVST:RtspPocoEvent] {FB280700} -  RTSP-XNvEvent Polling failed: 0, rc: 408
    ERROR [NVST:UdpRtpSource] {F9A7D700} -  UDP RTP Source: failed to receive data (Error: 0x80000013)
    ERROR [NVST:RtpSourceQueue] {F9A7D700} -  RtpSourceQueue: failed to read RTP packet (Result: 0X80000013)
    ERROR [BifrostClient: NvscWrapper] {1D0CF700} - Received old frame - current 7536 received 0
    ERROR [BifrostClient: Interface] {2B436200} - nvbSendInputEvent(). SessionIdentifier is ''
  5. Error similar to the below can be ignored when disabling and enabling again the Onshape Importer/ STEP Importer / URDF Importer Extensions:

    2021-06-01 19:16:51 [65,842ms] [Error] [carb.settings.python] AttributeError: 'NoneType' object has no attribute '...'
  6. If you see this error “Could not find registered CUDA function ‘updateBodyExternalVelocitiesLaunch”, please add import omni.physx before all of your import torch:

    import omni.physx
    import torch
  7. Do not source ROS2 in the terminal running Isaac Sim, standalone python scripts or Isaac Cortex as that can cause errors during startup because of conflicting symbols.

  8. Errors related to carb.flatcache and omni.graph when opening an asset can be ignored

    [Error] [carb.flatcache.plugin] Error: UsdRelationship Foo.inputs:targetPrims has multiple targets, which is not supported
    [Error] [carb.flatcache.plugin] Error: Foo/make_array.__resolved_outputs:array UsdRelationship not supported in GetPrimArrayAttr
    [Error] [omni.graph] Tried to set a value on AttributeData 'inputs:Foo' of type 'token' with incompatible data (Unable to cast Python instance to C++ type (compile in debug mode for details))
    [Error] [omni.graph] AttributeError: Attempted to get array size of non-array attribute inputs:Foo
  9. Errors related to destroyResourceBindingSignature() on exit can be ignored

    [Error] [] pipelineLayouts: 3 or descriptorSetLayouts: 3 is leaking memory. Missing call to destroyResourceBindingSignature()
  10. Errors related to shaderGroupHandle can be ignored

    [Error] [] shaderGroupHandle changed for shader group ***, missing from informerList,
  11. If an asset contains an Action Graph and the Action Graph window is closed before re-opening the same asset, the following errors may appear and can be ignored:

    [Error] [omni.usd] TF_PYTHON_EXCEPTION (secondary thread): in TfPyConvertPythonExceptionToTfErrors at line 114 of /buildAgent/work/ca6c508eae419cf8/USD/pxr/base/tf/pyError.cpp -- Tf Python Exception
    [Error] [] [py stderr]: sys:1: RuntimeWarning: coroutine 'OmniGraphModel.__delayed_prim_changed' was never awaited
    RuntimeWarning: Enable tracemalloc to get the object allocation traceback
    [Error] [omni.graph] Invalid GraphObj object in Py_Graph in getNode


  1. On Ubuntu 18.04 Disabling the ROS2 extension will cause Isaac Sim to hang due to a thread wait issue in the rclcpp cyclonedds backend.

  2. The WebSocket Client on Firefox may appear to hang after a few seconds when clicking the Play button. Using the Google Chrome or Chromium browser is recommended.

  3. Isaac Sim may hang if a browser pop-up for logging into Nucleus is closed before completing the login. Force restart of Isaac Sim is required.

  4. Isaac Sim may hang if it is shutdown from the File -> Exit Fast (Experimental) menu when using livestreaming. Please force close Isaac Sim and the livestream client when this happens.

  5. The Omniverse Streaming Client may hang after Isaac Sim exits with the File -> Exit menu. Please force close the Omniverse Streaming Client when this happens.

  6. Avoid dragging robots through the Gizmo or Properties panel while the simulation is running, otherwise error messages similar to the ones below may appear, and a significant slowdown that may be perceived as a system freeze may happen. Click on the stop simulation button and wait for it to settle.

    [Error] [omni.physx.plugin] PhysX error: PxGeometryQuery::getWorldBounds(): pose is not valid., FILE /buildAgent/work/99bede84aa0a52c2/source/geomutils/src/GuGeometryQuery.cpp, LINE 339
    [Error] [omni.physx.plugin] Transformation change on non-root links is not supported. Link: <...>