Package manager in Visual Studio 2015 "407 (Proxy Authentication Required)" - visual-studio

Question

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

I had the same problem a few weeks ago. For me it has helped to put in the the following in the machine.config (Windows/Microsoft.NET/Framework64/v4.0.30319/Config)
<system.net>
<settings>
<ipv6 enabled="True"/>
</settings>
<defaultProxy useDefaultCredentials="True" enabled="True">
<proxy proxyaddress="http://your.proxyserver.ip:port"/>
</defaultProxy>
</system.net>

Answer 2

I had to modify the 32 bit machine.config (assumption being VS runs in 32 bit) to add the <system.net> section but omitting anything within the <defaultProxy> tag:
<system.net>
<defaultProxy useDefaultCredentials="True" enabled="True" />
</system.net>
According to MSDN:
If the defaultProxy element is empty, the proxy settings from Internet Explorer will be used.
This is perfect for me as every other application on my machine works - including IE.
manchine.config location (Win 7): %SYSTEMROOT%\Microsoft.NET\Framework\v4.0.30319\Config\machine.config
Note
I resolved this thanks to #user3063127 pointing me in the right direction (you have an upvote). As far as I can tell this only affects package restore on DNX projects and may well be fixed when RC2 is released.

Answer 3

Updated to latest nuget.exe 1st
nuget update self
Added proxy details to the config file:
nuget config -Set http_proxy=http://username:password#proxyserver.company.com:port

Answer 4

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 5

If you have Fiddler installed, tick the option 'Automatically Authenticate' under the Rules option, should fix the above issue.
Selecting the Automatically Authenticate
Got this from the following post
Configuring Fiddler to use company network's proxy?

Answer 6

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.

Answer 7

Maybe you have wrong proxy credentials in Credential Manager. Try to remove it.
Control Panel -> User Account -> Credential Manager.
Remove proxy credentials resolved my problem.

Answer 8

Adding proxy username, password fixed my 407 authentication issue.
Place the following snippet in NuGet.config file located at C:\Users\myUserName\AppData\Roaming
<configuration>
<config>
<add key="http_proxy" value="http://my.proxy.address:port" />
<add key="http_proxy.user" value="mydomain\myUserName" />
<add key="http_proxy.password" value="[base64 encoded Password]" />
</config>
</configuration>
Ref: https://forums.asp.net/t/2096179.aspx?Proxy+407+Access+Denied