Unable to load the service index for source https://api.nuget.org/v3/index.json in VS2017?

Question

I am getting This error:

[nuget.org] Unable to load the service index for source https://api.nuget.org/v3/index.json. An error occurred while send

Answer 1

I was having same issue in VS 2017. You would need to enable proxy settings for VS, so that it can use existing IE proxy to reach out internet. This is especially useful, for those users, who uses office laptops and proxy settings are managed by group policies and IE settings get updated automatically. It would have been great if there was an option within VS IDE itself to add proxy just like Eclipse IDE has.

Solution

1. Go to your Visual Studio install location as below -

C:\Program Files (x86)\Microsoft Visual Studio\2017\Professional\Common7\IDE

2. Open devenv.exe.config file as an Administrator.

Add defaultProxy tags as below, within the existing system.net tag -

<system.net>
    <defaultProxy enabled="true" useDefaultCredentials="true">
        <proxy usesystemdefault="true" bypassonlocal="true" />
    </defaultProxy>
  <settings>
    <ipv6 enabled="true"/>
  </settings>
</system.net>

3. Restart VS.

Answer 2

download nupkg from https://www.nuget.org/

execute below command in cmd

dotnet new -i c:\some-folder\some-package.nupkg

Awesome Thanks to https://stackoverflow.com/a/62777292/14068039

Answer 3

Please go to Nuget.org and check if the Nuget is up.

Answer 4

I have faced the same problem with VS 2015 Go to the following folder

C:\Program Files (x86)\Microsoft Visual Studio 14.0\Common7\IDE

and add In my case is already present added the highlighted text

<system.net>
    **<defaultProxy enabled="true" useDefaultCredentials="true">
        <proxy usesystemdefault="true" bypassonlocal="true" />
    </defaultProxy>**
  <settings>
    <ipv6 enabled="true"/>
  </settings>
</system.net>

Solved my issue

Answer 5

TLDR ;)

FYI: the same issue is still happening for VS 2019 Version 16.6.3.

---

Ok, let's get started to fix this issue :)

First, you need to navigate the Visual Studio instance and for that do the following:

1. Open Properties on VS shortcut and then click on "Open File Location"

2. Edit as administrator the devenv.exe.config with Notepad++ or other editors you prefer:

3. Navigate to the end of a file and check if you don't have <defaultProxy>... section:

4. Make sure to add following inside <system.net>:

   <defaultProxy enabled="true" useDefaultCredentials="true">
      <proxy usesystemdefault="true" bypassonlocal="true" />
   </defaultProxy>

---

The final result should be like this:

A few notes:

1. If you have several Visual Studio instances then make sure you edited devenv.exe.config for each one.
2. Sometimes after VS updates, these files content can reset. So a good hint here is that once you Update Visual Studio instance, then go and check the .exe.config file.

---

Update: Btw, the same kind of approach work for many other applications, for example, check this post.

Answer 6

Another method - a workaround - Just do it manually!

I gave up all solutions provided in Github an SO.
Checking the Manage .NET project and item templates docs I just found out that I can install a package locally.

So if anyone is struggling with this, just download .nupkg the package from the source and use the following command

dotnet new -i c:\some-folder\some-package.nupkg

How to download a package manually

1. Go to Nuget.org
2. Search for your package and click to see the details
3. Locate the Download package link, located at the Info section.
4. Use the command shown above. Cheers! Package installed!