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

Change the "package source" in nuget to All

Details: None of the above helped in my case. My problem was that I restricted to only one private feed. Once I changed the "package source" to All, my problem was solved. I believe the crux of the matter is that my private pkg has a dependency on other pkgs from nuget.org.

I hope this can help someone

Answer 2

In general closing and re-open VS 2015 fixed most problems I have ran across. Once I did need to run a repair on one of my computers.

However I was about to do this Closing and re-opening VS2015 resolved the issue for me I figured that I would instead right click on the project and Unload Project then right click and Reload project THEN Manage Nuget worked!

Answer 3

I had this problem, which seemed to be caused by something broken in the solution level packages folder. I deleted the contents of the folder and let nuget install all the packages again.

I could then install new packages again.

Answer 4

In my case, nothing of the above helped. The root cause of the problem in my case was, that I uninstalled the package before and did not check in the change into source control (TFS in my case). After checking in the change (=the deletion of file in the packages folder), I could reinstall the package.

Answer 5

Some of your packages might not be supported by your type of project. For instance, you can't use RestSharp or Moq with UAP projects.

To get a better error message, try adding the package to your project.json file directly and then trying to build your solution.

Answer 6

In my case, This problem was caused by a mismatch in my Target framework setting under each project. When I created a new project, VS 2015 defaulted to 4.5.2, however all my nuget packages were built for 4.6.

For some reason, VS 2015 was not showing me these errors. I didn't see them until I created a new empty project and tried to add my nuget project there. This behavior may have been aggravated because I had renamed the project a few times during the initial setup.

I solved the problem by

• changing the Target Framework on my projects to 4.6
• closed VS 2015
• deleted "packages", "obj" and "bin" folders
• re-open the solution and try to add the nuget package again.