# Trouble with Extension Manager

**URL:** <https://discourse.slicer.org/t/trouble-with-extension-manager/2457>\
**Category:** Support\
**Tags:** extensions-manager\
**Created:** [March 28, 2018, 2:55pm UTC](https://discourse.slicer.org/t/trouble-with-extension-manager/2457 "2018-03-28T14:55:28Z")\
**Posts on this page:** 9\
**Page:** 1

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**Author:** ![lsmith](https://avatars.discourse-cdn.com/v4/letter/l/c77e96/32.png) [@lsmith](https://discourse.slicer.org/u/lsmith)\
**Post date:** [March 28, 2018, 2:55pm UTC](https://discourse.slicer.org/t/trouble-with-extension-manager/2457/1 "2018-03-28T14:55:28Z")

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I just downloaded 4.8.1 on my MacBook to test out the program for our work with DTI and tractography, and when I open the extension manager, it fails to load any of the extensions. It stops around 66% every time. I’ve tried shutting down the program and opening it back up, uninstalling and reinstalling, etc. I even downloaded the nightly build to see if it would work, and while it said it had loaded to 100%, no extensions would show up. Any suggestions?

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**Author:** ![ihnorton](https://sea2.discourse-cdn.com/flex002/user_avatar/discourse.slicer.org/ihnorton/32/9_2.png) [@ihnorton](https://discourse.slicer.org/u/ihnorton)\
**Post date:** [March 28, 2018, 2:57pm UTC](https://discourse.slicer.org/t/trouble-with-extension-manager/2457/2 "2018-03-28T14:57:00Z")

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Do you know if you are behind a firewall? Please try accessing this address in your web browser:

[https://slicer.kitware.com/midas3/slicerappstore](https://slicer.kitware.com/midas3/slicerappstore)

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**Author:** ![lsmith](https://avatars.discourse-cdn.com/v4/letter/l/c77e96/32.png) [@lsmith](https://discourse.slicer.org/u/lsmith)\
**Post date:** [March 28, 2018, 2:59pm UTC](https://discourse.slicer.org/t/trouble-with-extension-manager/2457/3 "2018-03-28T14:59:18Z")

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Yes, I am- that would explain it! I was able to download the extensions I needed from the site you linked. I appreciate your help!

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**Author:** ![ihnorton](https://sea2.discourse-cdn.com/flex002/user_avatar/discourse.slicer.org/ihnorton/32/9_2.png) [@ihnorton](https://discourse.slicer.org/u/ihnorton)\
**Post date:** [March 28, 2018, 3:01pm UTC](https://discourse.slicer.org/t/trouble-with-extension-manager/2457/4 "2018-03-28T15:01:05Z")

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Which OS? In principle we should be able to respect OS proxy settings in the extension manager, but we may not do it on all platforms right now.

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**Author:** ![lsmith](https://avatars.discourse-cdn.com/v4/letter/l/c77e96/32.png) [@lsmith](https://discourse.slicer.org/u/lsmith)\
**Post date:** [March 28, 2018, 3:02pm UTC](https://discourse.slicer.org/t/trouble-with-extension-manager/2457/5 "2018-03-28T15:02:14Z")

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Right now I’m on OS Sierra 10.12.6

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**Author:** ![Steve\_W](https://avatars.discourse-cdn.com/v4/letter/s/ba9def/32.png) [@Steve\_W](https://discourse.slicer.org/u/Steve_W)\
**Post date:** [April 3, 2018, 11:11am UTC](https://discourse.slicer.org/t/trouble-with-extension-manager/2457/6 "2018-04-03T11:11:04Z")

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Adding a PROXY option. I cant add plugins at work due to proxy!.

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**Author:** ![ihnorton](https://sea2.discourse-cdn.com/flex002/user_avatar/discourse.slicer.org/ihnorton/32/9_2.png) [@ihnorton](https://discourse.slicer.org/u/ihnorton)\
**Post date:** [April 3, 2018, 3:40pm UTC](https://discourse.slicer.org/t/trouble-with-extension-manager/2457/7 "2018-04-03T15:40:56Z")

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Hi @Steve_W, I moved your message over to this thread where there is a similar issue. For now, please see this document:

[https://www.slicer.org/wiki/Documentation/Nightly/SlicerApplication/ExtensionsManager#How\_to\_manually\_download\_an\_extension\_package.3F](https://www.slicer.org/wiki/Documentation/Nightly/SlicerApplication/ExtensionsManager#How_to_manually_download_an_extension_package.3F)

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**Author:** ![ihnorton](https://sea2.discourse-cdn.com/flex002/user_avatar/discourse.slicer.org/ihnorton/32/9_2.png) [@ihnorton](https://discourse.slicer.org/u/ihnorton)\
**Post date:** [April 3, 2018, 3:50pm UTC](https://discourse.slicer.org/t/trouble-with-extension-manager/2457/8 "2018-04-03T15:50:13Z")

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@lsmith @Steve_W I did a quick test running through a local proxy on my computer (macOS 10.12; Slicer-4.8.1 and Slicer preview/nightly 3/22/18). The proxy was configured with [SquidMan](http://squidman.net/squidman/) and enabled in Network Preferences.

The extension manager seems to work correctly (loads the list and installs an extension), and watching the squid access log after starting Slicer, I was able to verify that all traffic (both HTTP and HTTPS) is running through the proxy. So given that the issue can’t be reproduced in a simple way, we will need some debugging on your side… To start, please look at the [error log](https://www.slicer.org/wiki/Documentation/Nightly/SlicerApplication/ErrorLog) and terminal, and post any error messages that may be there.

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**Author:** ![jcfr](https://sea2.discourse-cdn.com/flex002/user_avatar/discourse.slicer.org/jcfr/32/17825_2.png) [@jcfr](https://discourse.slicer.org/u/jcfr)\
**Post date:** [April 4, 2018, 5:18am UTC](https://discourse.slicer.org/t/trouble-with-extension-manager/2457/9 "2018-04-04T05:18:13Z")

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This is where we configure the proxy settings:

> <https://github.com/Slicer/Slicer/blob/c30c6be815aa0c3a0fd8c31f6ad9f9ff272df12c/Base/QTCore/qSlicerCoreApplication.cxx#L322-L323>

And to learn more about how Qt use the system configuration:

See [https://doc.qt.io/qt-5/qnetworkproxyfactory.html#setUseSystemConfiguration](https://doc.qt.io/qt-5/qnetworkproxyfactory.html#setUseSystemConfiguration)