# vtk.js@21.1.2 error：regeneratorRuntime is not defined

**URL:** https://discourse.vtk.org/t/vtk-js-21-1-2-error-regeneratorruntime-is-not-defined/7278
**Category:** Web
**Created:** [November 26, 2021, 7:35am UTC](https://discourse.vtk.org/t/vtk-js-21-1-2-error-regeneratorruntime-is-not-defined/7278 "2021-11-26T07:35:13Z")
**Posts on this page:** 3
**Page:** 1

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### Author: ![lanranlaura](https://discourse.vtk.org/user_avatar/discourse.vtk.org/lanranlaura/32/3748_2.png) [@lanranlaura](https://discourse.vtk.org/u/lanranlaura)
#### Post date: [November 26, 2021, 7:35am UTC](https://discourse.vtk.org/t/vtk-js-21-1-2-error-regeneratorruntime-is-not-defined/7278/1 "2021-11-26T07:35:13Z")

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Hello！I have a new problem. I updated the version of vtk.js from 17.0 to 21.1.2, but the statement vtkOpenGLRenderWindow. newnstance() reported an error during npm run dev, as shown in the figure below.  
 ![image](https://discourse.vtk.org/uploads/default/original/2X/a/a601ac15d160bcc6ba1eab0166e0abfece481ce7.png)  
My Babel configuration is shown in the figure below.Is there any solution?  
 ![image](https://discourse.vtk.org/uploads/default/original/2X/4/4541dfa61460083987ddd2982dc1c8007b02312b.png)

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### Author: ![Sebastien\_Jourdain](https://discourse.vtk.org/user_avatar/discourse.vtk.org/sebastien_jourdain/32/100_2.png) [@Sebastien\_Jourdain](https://discourse.vtk.org/u/Sebastien_Jourdain)
#### Post date: [November 28, 2021, 11:29pm UTC](https://discourse.vtk.org/t/vtk-js-21-1-2-error-regeneratorruntime-is-not-defined/7278/2 "2021-11-28T23:29:08Z")

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That issue is [tracked here](https://github.com/Kitware/vtk-js/issues/1882) with probably a solution for your usage.

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### Author: ![Forrest](https://discourse.vtk.org/user_avatar/discourse.vtk.org/forrest/32/300_2.png) [@Forrest](https://discourse.vtk.org/u/Forrest)
#### Post date: [November 29, 2021, 7:36pm UTC](https://discourse.vtk.org/t/vtk-js-21-1-2-error-regeneratorruntime-is-not-defined/7278/3 "2021-11-29T19:36:57Z")

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Easiest solution should be to install `regenerator-runtime`. We may need to add it as a peer or regular dependency…