# Odd behaviour with Processing 3 and Processing 4 installed

**URL:** <https://discourse.processing.org/t/odd-behaviour-with-processing-3-and-processing-4-installed/31725>\
**Category:** Processing\
**Created:** [August 14, 2021, 2:44pm UTC](https://discourse.processing.org/t/odd-behaviour-with-processing-3-and-processing-4-installed/31725 "2021-08-14T14:44:37Z")\
**Posts on this page:** 4\
**Page:** 1

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**Author:** ![PhilHaw](https://yyz2.discourse-cdn.com/flex036/user_avatar/discourse.processing.org/philhaw/32/8221_2.png) [@PhilHaw](https://discourse.processing.org/u/PhilHaw)\
**Post date:** [August 14, 2021, 2:44pm UTC](https://discourse.processing.org/t/odd-behaviour-with-processing-3-and-processing-4-installed/31725/1 "2021-08-14T14:44:37Z")

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I have Processing 3 (3.5.4) and Processing 4.0b1 installed on a Windows 10 PC.

Here’s an odd thing! If I have Processing 3 open and I try to run Processing 4, the Processing 4 splash screen appears briefly but the new sketch opens in Processing 3.

When I quit both but run Processing 4 first, then try to open Processing 3, the P3 splash screen appears briefly but the new sketch opens in P4!

Has anyone else experienced this?

Phil

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**Author:** ![behreajj](https://avatars.discourse-cdn.com/v4/letter/b/b5a626/32.png) [@behreajj](https://discourse.processing.org/u/behreajj)\
**Post date:** [August 14, 2021, 2:58pm UTC](https://discourse.processing.org/t/odd-behaviour-with-processing-3-and-processing-4-installed/31725/2 "2021-08-14T14:58:48Z")

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> <https://github.com/processing/processing4/issues/244>
>
> \## Description
> When Processing 4 is open and I go to open Processing 3, another… instance of Processing 4 opens.
> Likewise, when Processing 3 is open and I go to open Processing 4, another instance of Processing 3 opens.
> 
> On the contrary, when either is opened when the other is still loading (at its splash screen), then both versions open as expected.
> 
> \## Your Environment
> \* Processing version:
> \* Operating System and OS version: Windows 10

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<div class="post-metadata">

**Author:** ![PhilHaw](https://yyz2.discourse-cdn.com/flex036/user_avatar/discourse.processing.org/philhaw/32/8221_2.png) [@PhilHaw](https://discourse.processing.org/u/PhilHaw)\
**Post date:** [August 14, 2021, 3:45pm UTC](https://discourse.processing.org/t/odd-behaviour-with-processing-3-and-processing-4-installed/31725/3 "2021-08-14T15:45:05Z")

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Thanks @behreajj . I did search this forum but didn’t find this!

The behaviour is consistent with this on macOS also.

Phil.

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**Author:** ![GoToLoop](https://yyz2.discourse-cdn.com/flex036/user_avatar/discourse.processing.org/gotoloop/32/86_2.png) [@GoToLoop](https://discourse.processing.org/u/GoToLoop)\
**Post date:** [August 14, 2021, 9:22pm UTC](https://discourse.processing.org/t/odd-behaviour-with-processing-3-and-processing-4-installed/31725/4 "2021-08-14T21:22:08Z")

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AFAIK only version which can be opened at the same time as another version of Processing is v1. 🤓