Visual Studio 2010 nuget error: The underlying connection was closed: Could not establish trust relationship for the SSL/TLS secure channel

Question

Whenever I\'m trying to install something or even just list the packages I get this error \"The underlying connection was closed: Could not establish trust relationship for

Answer 1

If nothing from above works, try this....

Try pasting the following into a .reg file and run it. Then try running your NuGet command (no reboot required).

Windows Registry Editor Version 5.00

[HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft.NETFramework\v4.0.30319] "SchUseStrongCrypto"=dword:00000001

[HKEY_LOCAL_MACHINE\SOFTWARE\Wow6432Node\Microsoft.NETFramework\v4.0.30319] "SchUseStrongCrypto"=dword:00000001

Ran into this issue because TLS1.2 was not enabled (similar to Tony's response). Using http does not fix the situation because NuGet redirects to https now that TLS1.2 is enforced.

thanks to "neoscribe"

Answer 2

As of today 21-Jan-2015, the correct url is https://www.nuget.org/api/v2/. The www is required or the certificate fails. Do NOT fall back to http because you are opening your code and all of its consumers to a nasty MITM vector.

Answer 3

Go to https://nuget.org/ and get its certificate.

For example, if you're using Firefox: after opening nuget site - click site's icon on the left side of address bar, click 'More Information', and on the Security tab there should be 'Web-site identity' section with 'View certificate' button. Click there, in the opened dialog select Details tab - there you should see chain for *.nuget.org. Click button 'Export' at the bottom and save certificate to the file (add .cer extension manually, because dialog won't do it for you).

Now you need to setup you system so that it will trust the certificate. Press Win+R (Run dialog will be opened) -> type mmc there and run it (with admin privileges if you have UAC turned on). There select File -> Add or remove snapin... -> select Certificates on the left, in the dialog select Computer account and Local computer. Click OK - the tree will have Certificates node in the Console root. Open it and file folder Trusted People. From its context menu select All tasks -> Import... -> Select file that you have exported before and import it.

Everything should be working fine.

Answer 4

Related: ServicePointManager does not support proxies with the https scheme

If you've previously had Fiddler open, you might well have a certificate for nuget.org that is invalid.

If so, open up MMC, add the Certificates snapin (current User) and remove nuget.org from the Personal store.

Due to Nuget keeping a handle to this cert (seemingly) you will have to restart Visual Studio. Afterwards, you should have a good time.

Answer 5

Go to VS2012 -> Tools -> Library Package Manager -> Package Manager Settings Choose Package Manager -> Package Sources.

1. Add a new package source as: Name= NugetSource Source= http://packages.nuget.org/v1/FeedService.svc/
2. Move Up the newly added package source to first position.
3. UnCheck existing "Nuget official package source"
4. Restart VS2012.

This is working on my machine.

Answer 6

• Go to VS2010 → Tools → Library Package Manager → Package Manager Settings.

• Choose Package Manager → Package Sources.

• Add a new package source as:

  • Name: NugetSource

  • Source: http://packages.nuget.org/v1/FeedService.svc/

• Move Up the newly added package source to first position.

• UnCheck existing "Nuget official package source"

• Restart VS2010.