# Error when activating p5.js mode in Desktop

**URL:** <https://discourse.processing.org/t/error-when-activating-p5-js-mode-in-desktop/46336>\
**Category:** p5.js\
**Created:** [May 6, 2025, 8:41pm UTC](https://discourse.processing.org/t/error-when-activating-p5-js-mode-in-desktop/46336 "2025-05-06T20:41:24Z")\
**Posts on this page:** 3\
**Page:** 1

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**Author:** ![edwin\_isensee](https://yyz2.discourse-cdn.com/flex036/user_avatar/discourse.processing.org/edwin_isensee/32/7705_2.png) [@edwin\_isensee](https://discourse.processing.org/u/edwin_isensee)\
**Post date:** [May 6, 2025, 8:41pm UTC](https://discourse.processing.org/t/error-when-activating-p5-js-mode-in-desktop/46336/1 "2025-05-06T20:41:24Z")

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I just installed Processing 4.4.1 on my Windows 11 laptop. After that, I installed the p5.js mode. Everything went fine. However, when I try to activate the p5.js mode, I receive a weird message saying “A nasty error occurred while trying to use p5.js”. And the app gois back to Java mode. Has anyone ever faced this?

 ![p5.js mode error](https://canada1.discourse-cdn.com/flex036/uploads/processingfoundation1/original/3X/5/d/5dab8b2c2dcb75291cdf55b26a6bfa379158e942.png)

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**Author:** ![svan](https://avatars.discourse-cdn.com/v4/letter/s/82dd89/32.png) [@svan](https://discourse.processing.org/u/svan)\
**Post date:** [May 6, 2025, 9:14pm UTC](https://discourse.processing.org/t/error-when-activating-p5-js-mode-in-desktop/46336/2 "2025-05-06T21:14:43Z")

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I get the same error message when trying to open p5.js mode in Processing 4.4.1 on macOS.

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**Author:** ![ProcessingOrg](https://yyz2.discourse-cdn.com/flex036/user_avatar/discourse.processing.org/processingorg/32/18341_2.png) [@ProcessingOrg](https://discourse.processing.org/u/ProcessingOrg)\
**Post date:** [May 6, 2025, 10:03pm UTC](https://discourse.processing.org/t/error-when-activating-p5-js-mode-in-desktop/46336/3 "2025-05-06T22:03:14Z")

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Hi @edwin_isensee and @svan and thanks for your messages.

The issue has been fixed in 4.4.3 (currently in beta). You can download it from the Processing website.

See this previous discussion below.

> [@Can't switch to p5.js mode](https://discourse.processing.org/t/cant-switch-to-p5-js-mode/46252/3):
>
> Seeing the same on Windows but not on Mac surprisingly. In any case, here is a PR that will fix this issue: [Added missing module by Stefterv · Pull Request #1056 · processing/processing4 · GitHub](https://github.com/processing/processing4/pull/1056)