# I can't edit extension source codes. Edit button is not run
**URL:** https://discourse.slicer.org/t/i-cant-edit-extension-source-codes-edit-button-is-not-run/30538
**Category:** Support
**Created:** [July 12, 2023, 5:56am UTC](https://discourse.slicer.org/t/i-cant-edit-extension-source-codes-edit-button-is-not-run/30538 "2023-07-12T05:56:54Z")
**Posts on this page:** 2
**Page:** 1
### Author:  [@Muhammed\_Fatih\_Talu](https://discourse.slicer.org/u/Muhammed_Fatih_Talu)
#### Post date: [July 12, 2023, 5:56am UTC](https://discourse.slicer.org/t/i-cant-edit-extension-source-codes-edit-button-is-not-run/30538/1 "2023-07-12T05:56:54Z")
When we want to update the source code of any extension, we use the EDIT button. When the button is pressed, a code editor installed on the computer is activated and the relevant code is opened. Unfortunately, when I press the EDIT button, the code editor does not open. Nothing happens.
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### Author:  [@lassoan](https://discourse.slicer.org/u/lassoan)
#### Post date: [July 12, 2023, 7:10pm UTC](https://discourse.slicer.org/t/i-cant-edit-extension-source-codes-edit-button-is-not-run/30538/2 "2023-07-12T19:10:55Z")
Slicer opens the the .py file in the program that is specified in operating system settings. If you want to use a different program (e.g., because when you installed Python you chose to associate .py files with the Python launcher) then you can [specify an editor in the Slicer application settings](https://discourse.slicer.org/t/editor-for-py-files-is-now-configurable/30563). This feature is only available in latest Slicer Preview Releases.