# \[Error\] \[carb.python\] Failed to reload python module pxr.Tf. Error: module pxr.Tf.\_tf not in sys.modules

**URL:** <https://forums.developer.nvidia.com/t/error-carb-python-failed-to-reload-python-module-pxr-tf-error-module-pxr-tf-tf-not-in-sys-modules/193752>\
**Category:** Samples & Examples\
**Tags:** omnikithelper, python\
**Created:** [November 2, 2021, 9:12am UTC](https://forums.developer.nvidia.com/t/error-carb-python-failed-to-reload-python-module-pxr-tf-error-module-pxr-tf-tf-not-in-sys-modules/193752 "2021-11-02T09:12:14Z")\
**Posts on this page:** 1\
**Page:** 1

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**Author:** ![usdvh](https://developer.download.nvidia.com/images/forums/profile-default-devtalk-84.png) [@usdvh](https://forums.developer.nvidia.com/u/usdvh)\
**Post date:** [November 2, 2021, 9:12am UTC](https://forums.developer.nvidia.com/t/error-carb-python-failed-to-reload-python-module-pxr-tf-error-module-pxr-tf-tf-not-in-sys-modules/193752/1 "2021-11-02T09:12:14Z")

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I’m trying to launch a Isaac Sim python application and the following Error is showing up:

 ![image](https://global.discourse-cdn.com/nvidia/original/3X/2/9/293a0837802a88c20b75a89a6e20b53e77245c7f.png)

I don’t get what is going on, because Im only lunching the OmniKitHelper with a simple CONFIG, as showed here:

 ![image](https://global.discourse-cdn.com/nvidia/original/3X/9/1/912aea0dfd703920cb8b869a19b32c9ffd52c32d.png)

I attached also the log File… I would appreciate if someone can tellme whats the problem.  
[kit\_20211102\_205923.log](https://forums.developer.nvidia.com/uploads/short-url/w5o4oAcin9GT6HOq5F5csGVcVCC.log) (151.7 KB)