Package manager in Visual Studio 2015 “407 (Proxy

Question

I understand this is an often asked question, however after days of research I've not found an answer to this particular problem.

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I have a new ASP.NET 5 (Core 1.0) MVC template that I'm trying to add a package to however each and every time I get in the Package Manager output:

Response status code does not indicate success: 407 (Proxy Authentication Required). 

and the following at the top of solution explorer:

my settings look fine and I am able to browse packages in the 'Manage Packages for Solution' screen.

I understand I'm being requested to supply credentials so where do I enter them? On the other hand all other applications on my machine have validated internet access, so why should I?

Any ideas / pointers are very welcome.

Visual Studio 2015 - 14.0.24720.00 Update 1
NuGet Package Manager for Visual Studio 2015 - 3.3.0.167

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Top section of Package Manager output:

Installing NuGet package AutoMapper.4.2.1.
Successfully installed 'AutoMapper 4.2.1' to CustomerPortal
========== Finished ==========
PATH=.\node_modules.bin;%PATH%;C:\Program Files (x86)\Microsoft Visual Studio 14.0\Common7\IDE\Extensions\Microsoft\Web Tools\External;C:\Program Files (x86)\Microsoft Visual Studio 14.0\Common7\IDE\Extensions\Microsoft\Web Tools\External\git
C:\Users\medmondson.dnx\runtimes\dnx-clr-win-x86.1.0.0-rc1-update1\bin\dnx.exe "C:\Users\medmondson.dnx\runtimes\dnx-clr-win-x86.1.0.0-rc1-update1\bin\lib\Microsoft.Dnx.Tooling\Microsoft.Dnx.Tooling.dll" restore "M:\visual studio 2015\Projects\CustomerPortal\src\CustomerPortal" -f "C:\Program Files (x86)\Microsoft Web Tools\DNU"
Microsoft .NET Development Utility Clr-x86-1.0.0-rc1-16231
GET https://www.nuget.org/api/v2/
GET http://packages.nuget.org/v1/FeedService.svc/
GET https://www.postsharp.net/nuget/packages/
Restoring packages for M:\visual studio 2015\Projects\CustomerPortal\src\CustomerPortal\project.json
GET https://www.nuget.org/api/v2/FindPackagesById()?id='AutoMapper'
GET http://packages.nuget.org/v1/FeedService.svc/FindPackagesById()?id='AutoMapper'
GET https://www.postsharp.net/nuget/packages/FindPackagesById()?id='AutoMapper'
Warning: FindPackagesById: AutoMapper
An error occurred while sending the request.
GET https://www.nuget.org/api/v2/FindPackagesById()?id='AutoMapper'
GET https://www.nuget.org/api/v2/FindPackagesById()?id='System.Collections.Immutable'
GET http://packages.nuget.org/v1/FeedService.svc/FindPackagesById()?id='System.Collections.Immutable'
GET https://www.postsharp.net/nuget/packages/FindPackagesById()?id='System.Collections.Immutable'
Warning: FindPackagesById: AutoMapper
An error occurred while sending the request.
GET https://www.postsharp.net/nuget/packages/FindPackagesById()?id='AutoMapper'
Warning: FindPackagesById: AutoMapper
Response status code does not indicate success: 407 (Proxy Authentication Required).

Update

I've managed to capture a non-working request (returning 407) and a working request with the only difference being the content of the Proxy-Authorization header which is longer. This would suggest the proxy authentication does exist but it's using a different protocol.

Answer 1

You need to modify file 2 .config files:

for Visual Studio 2015

• C:\Program Files (x86)\Microsoft Visual Studio 14.0\Common7\IDE\vsn.exe.config
• C:\Program Files (x86)\Microsoft Visual Studio 14.0\Common7\IDE\devenv.exe.config

for Visual Studio 2017

• C:\Program Files (x86)\Microsoft Visual Studio\2017\Community\Common7\IDE\vsn.exe.config
• C:\Program Files (x86)\Microsoft Visual Studio\2017\Community\Common7\IDE\devenv.exe.config

<system.net>
  <defaultProxy enabled="true" useDefaultCredentials="true">
    <proxy usesystemdefault="True" bypassonlocal="True" proxyaddress="http://yourproxy:proxyport" />
    <bypasslist>
      <add address="(.*\.)?anyotherdomain\.com?(.*)" />
      <add address="(.*\.)?nuget\.org?(.*)" />
      <add address="192\.168\.\d{1,3}\.\d{1,3}" />
    </bypasslist>
  </defaultProxy>
  <settings>
    <ipv6 enabled="false"/>
    <servicePointManager expect100Continue="false"/>
  </settings>
</system.net>

The bypass for nuget.org will work if, without the proxy, you still can get it's IP from DNS server and nothing else is blocking it.

Also need this to install nuget

Open the file C:\Users\[YOUR_USER_NAME]\AppData\Roaming\NuGet\NuGet.Config and add inside the <configuration> <\configuration> tag the following:

<config>
  <add key="http_proxy" value="http://yourproxy:proxyport" />
</config>

Taken from Marco Mengoli's Blog

Answer 2

If you don't know the proxy server details, you can go with other workaround to overcome this error "407 (Proxy Authorisation Required.)"

Workaround: 1. Download/Install Fiddler 2. Click Menu Rules -> Automatically Authenticate

Without closing Fiddler, now try to do restore package in Visual Studio. It should now restore the packages without any proxy error.

This is not a neat solution, but still an alternate workaround to resolve this issue. This solution tries to utilise Fiddler as Proxy.