NuGet "Gather Dependencies" Hangs

When I add a NuGet package (latest version of NuGet and Visual Studio 2015) it hangs at "Attempting to gather dependencies" for ~5 minutes before installing the package. I can point to NuGet.org, our internal server, or a folder on my local machine. All behave exactly the same.

After a lot of digging (I had this issue for a long time before posting) I found the issue. One of the NuGet package sources in my list was down. If I remove that from the list, everything goes smoothly. With it in, it bogs down even if no packages in my packages.config are related to that source.

I struggled with the same issue for too long and almost all the advice I read was to update nuget VS extension (I'm using VS package manager console) or restart VS and nothing worked...

My setup (at time of issue):

• VS 2015 Pro Update 2
• Package Manager Console Host Version 3.4.3.855

Solution that finally worked for me:

1. Close VS if open.
2. Delete %AppData%\NuGet\NuGet.Config
3. Open VS and package manager console (this will recreate Nuget.config)

This updated my nuget.org feed to no longer point to www.nuget.org/api/v2 (see image below)

4. My Microsoft and .NET feed was also selected and I had to deselect that too:

After this installing packages no longer hung on 'Attempting to gather dependency information for package...'

Kudos to https://stackoverflow.com/a/36461793/4977243 for the idea of deleting nuget.config.

This morning, all of our builds started failing. After doing some digging, we figured out that it was hanging on https://www.nuget.org/api/v2 while resolving dependencies. More digging, it was connecting and downloading but seemed to be caught in a loop. Each time we cancelled the build, it left a Nuget.exe running in the background - CPU got hot.

Turns out that nuget.org upgraded their servers last night (1/13/2016) and the version of Nuget.exe that our builds were running (2.7.2) was choking.

The fix (at least for us) was to upgrade to 2.8.6 (https://dist.nuget.org/win-x86-commandline/v2.8.6/nuget.exe). I know that isn't the most current version but it worked for us. We'll upgrade later after the smoke dissipates!