# Psychopy on Big Sur on mac

**URL:** <https://discourse.psychopy.org/t/psychopy-on-big-sur-on-mac/18095>\
**Category:** Builder\
**Created:** [November 13, 2020, 11:26am UTC](https://discourse.psychopy.org/t/psychopy-on-big-sur-on-mac/18095 "2020-11-13T11:26:11Z")\
**Posts on this page:** 1\
**Showing post:** 2

<div class="post-metadata">

**Author:** ![TarandeepKang](https://sea2.discourse-cdn.com/flex002/user_avatar/discourse.psychopy.org/tarandeepkang/32/11793_2.png) [@TarandeepKang](https://discourse.psychopy.org/u/TarandeepKang)\
**Post date:** [November 13, 2020, 11:56am UTC](https://discourse.psychopy.org/t/psychopy-on-big-sur-on-mac/18095/2 "2020-11-13T11:56:44Z")

</div>

@Jon Gives some instructions here: [Release 2020.2.3 fixing launch issues for macOS Catalina/Mojave](https://discourse.psychopy.org/t/release-2020-2-3-fixing-launch-issues-for-macos-catalina-mojave/15886/6). It appears that the issue has something to do withA piece of background software called piglet.He writes:

Fetch your open copy of pyglet/window/key.py:  
[https://github.com/pyglet/pyglet/blob/pyglet-1.5-maintenance/pyglet/window/key.py](https://github.com/pyglet/pyglet/blob/pyglet-1.5-maintenance/pyglet/window/key.py) and save it inside psychopy/app/builder/

Then change `psychopy/app/builder/validators.py` around line 27 from

```auto
from pyglet.window import key

```

to

```auto
try:
    from pyglet.window import key
except Exception:
    from . import key

```

Hopefully then you can launch the app"

Unfortunately, I lack the technical skills to follow this instruction, Because I don’t know how to access the directory “`psychopy/app/builder/”.

I think if you follow the instructions above you should have solved the problem, can anyone point me to how to access this directory?

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