# Mac preview release fails to load extensions in the Extension Manager

**URL:** <https://discourse.slicer.org/t/mac-preview-release-fails-to-load-extensions-in-the-extension-manager/46612>\
**Category:** Support\
**Tags:** extensions-manager\
**Created:** [March 30, 2026, 2:25pm UTC](https://discourse.slicer.org/t/mac-preview-release-fails-to-load-extensions-in-the-extension-manager/46612 "2026-03-30T14:25:56Z")\
**Posts on this page:** 6\
**Page:** 1

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**Author:** ![DeepaKrishnaswamy](https://sea2.discourse-cdn.com/flex002/user_avatar/discourse.slicer.org/deepakrishnaswamy/32/8913_2.png) [@DeepaKrishnaswamy](https://discourse.slicer.org/u/DeepaKrishnaswamy)\
**Post date:** [March 30, 2026, 2:25pm UTC](https://discourse.slicer.org/t/mac-preview-release-fails-to-load-extensions-in-the-extension-manager/46612/1 "2026-03-30T14:25:56Z")

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Hi,

I installed the latest Slicer Preview Release 2026-03-29 (Slicer 5.11.0 revision 34472) on Mac. I noticed that the extensions are not loading in the Extensions Manager:

 ![Screenshot 2026-03-30 at 10.24.34 AM](https://us1.discourse-cdn.com/flex002/uploads/slicer/original/3X/f/e/fe7fa605345d83456b24fba2d0b65bda54632fdd.png)

I checked cdash and noticed many errors, even for extensions that should work like SlicerRT.

Thanks!

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**Author:** ![pieper](https://sea2.discourse-cdn.com/flex002/user_avatar/discourse.slicer.org/pieper/32/8_2.png) [@pieper](https://discourse.slicer.org/u/pieper)\
**Post date:** [March 30, 2026, 3:10pm UTC](https://discourse.slicer.org/t/mac-preview-release-fails-to-load-extensions-in-the-extension-manager/46612/2 "2026-03-30T15:10:02Z")

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Thanks for reporting.

Yes, it looks like pretty much [everything](https://slicer.cdash.org/index.php?project=SlicerPreview) is failing on the preview, while the stable look more normal.

 ![image](https://us1.discourse-cdn.com/flex002/uploads/slicer/original/3X/9/5/95cee1a5acd2c1cdf35d68d00ac294c452763f3d.jpeg)

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**Author:** ![fedorov](https://sea2.discourse-cdn.com/flex002/user_avatar/discourse.slicer.org/fedorov/32/14_2.png) [@fedorov](https://discourse.slicer.org/u/fedorov)\
**Post date:** [March 30, 2026, 9:59pm UTC](https://discourse.slicer.org/t/mac-preview-release-fails-to-load-extensions-in-the-extension-manager/46612/3 "2026-03-30T21:59:12Z")

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> [@pieper](#):
>
> it looks like pretty much [everything](https://slicer.cdash.org/index.php?project=SlicerPreview) is failing on the preview

AND it seems that pretty much [everything](https://slicer.cdash.org/viewBuildGroup.php?project=SlicerPreview&buildgroup=Extensions-Nightly&date=2026-03-30&) has been failing since March 22!

@Sunderlandkyl this can’t be related to the Girder work you’ve been doing, right?…

 ![image](https://us1.discourse-cdn.com/flex002/uploads/slicer/original/3X/7/a/7a577a794d3fa8a50456f6c4509ed6b46e85073f.png)

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**Author:** ![Sunderlandkyl](https://sea2.discourse-cdn.com/flex002/user_avatar/discourse.slicer.org/sunderlandkyl/32/79987_2.png) [@Sunderlandkyl](https://discourse.slicer.org/u/Sunderlandkyl)\
**Post date:** [March 31, 2026, 2:59pm UTC](https://discourse.slicer.org/t/mac-preview-release-fails-to-load-extensions-in-the-extension-manager/46612/4 "2026-03-31T14:59:44Z")

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Yes unfortunately… The PR updating the girder plugin has been integrated so hopefully it will be resolved soon.

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**Author:** ![Sam\_Horvath](https://sea2.discourse-cdn.com/flex002/user_avatar/discourse.slicer.org/sam_horvath/32/3092_2.png) [@Sam\_Horvath](https://discourse.slicer.org/u/Sam_Horvath)\
**Post date:** [March 31, 2026, 5:12pm UTC](https://discourse.slicer.org/t/mac-preview-release-fails-to-load-extensions-in-the-extension-manager/46612/5 "2026-03-31T17:12:56Z")

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Update, factory clients are updated, so uploads of packages will work again. next is updating the extension server

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**Author:** ![fedorov](https://sea2.discourse-cdn.com/flex002/user_avatar/discourse.slicer.org/fedorov/32/14_2.png) [@fedorov](https://discourse.slicer.org/u/fedorov)\
**Post date:** [April 1, 2026, 3:46pm UTC](https://discourse.slicer.org/t/mac-preview-release-fails-to-load-extensions-in-the-extension-manager/46612/6 "2026-04-01T15:46:06Z")

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Looks like extensions are back! Thank you for fixing this @Sam_Horvath and @Sunderlandkyl!

 ![image](https://us1.discourse-cdn.com/flex002/uploads/slicer/original/3X/1/0/10e1444942352607834201cf374aed7142a5678e.png)