Unable to Install Any Package in Visual Studio 201

Question

I've tried every package I could possibly find and none of them will install in my project. I've installed every update listed in the Extensions and Updates list that were available. When I attempt to install SendGrid for example, this is the result (as is the result with all other packages):

Attempting to gather dependencies information for package 'Sendgrid.6.1.0' with respect to project 'UI\MyApplication.MVC', targeting '.NETFramework,Version=v4.5.2'
Attempting to resolve dependencies for package 'Sendgrid.6.1.0' with DependencyBehavior 'Lowest'
Resolving actions to install package 'Sendgrid.6.1.0'
Resolved actions to install package 'Sendgrid.6.1.0'
For adding package 'SendGrid.SmtpApi.1.3.1' to project 'MyApplication.MVC' that targets 'net452'.
For adding package 'SendGrid.SmtpApi.1.3.1' to project 'MyApplication.MVC' that targets 'net452'.
Adding package 'SendGrid.SmtpApi.1.3.1' to folder 'C:\Users\Keith\Source\Workspaces\MyApplication\MyApplication.MVC\packages'
Install failed. Rolling back...

I can't be the only one on the planet having issue with Visual Studio 2015 and the new and "improved" NuGet Package Manager.

UPDATE:
Well, must be something odd in my solution because I created a new project from the VS2015 template (web) and the packages install just fine. When I find out the issue, I'll post the resolution in the event others run into the same problem.

UPDATE 2:
Ok, it's not our solution. We created a new solution from scratch again (this has wasted a lot of our development time might I add), added a couple of packages (Identity, EF, SendGrid) and after checking the solution in to VSO, another developer performs a fresh creation of the branch and build errors occur. When I go to the NuGet packages for an individual project, it acts as though none of the packages I have added are available. Anyone else experiencing this?

Answer 1

tl;dr - Delete this:

%AppData%/Nuget/Nuget.config

Warning: If you had custom NuGet sources, this will remove them, and you'll have to re-add them.

---

Longer version:

You might have corrupted your NuGet config. Oh no :(

Nuget.config is a file used to keep track of all of the places that NuGet pulls from, as well as configuring other things. More likely than not, this xml file got broken somehow.

• Go to this path: C:\Users\{{username}}\AppData\Roaming\
• Delete Nuget.config
• Restart VS for good measure

---

For reference: in the good days of 2017, your file should look something like this

<?xml version="1.0" encoding="utf-8"?>
<configuration>
  <packageRestore>
    <add key="enabled" value="True" />
    <add key="automatic" value="True" />
  </packageRestore>
  <activePackageSource>
    <add key="nuget.org" value="https://api.nuget.org/v3/index.json" />
  </activePackageSource>
  <packageSources>
    <add key="nuget.org" value="https://api.nuget.org/v3/index.json" protocolVersion="3" />
    <add key="nuget.org" value="https://www.nuget.org/api/v2/" />
    <!-- Others -->
  </packageSources>
  <packageSourceCredentials>
    <!-- secret stuff -->
  </packageSourceCredentials>
</configuration>

Answer 2

My guess is Nuget Package Manager is messing up with VSO. I create a new project, add packages to it just fine, check in TFS. Then I go home, "Get Latest Version", and Run, and fail because Nuget Package Manager doesn't restore my packages. Solution: on my home machine

1. open Nuget Package Manger, uninstall every packaged that have installed
2. Open References folder, right click > Delete for all the packages you've installed
3. Re-install them via Nuget Package Manager
4. Check in