NuGet is returning 503 Server Unavailable

Question

Is there a way to load a package from an alternative server when Visual Studio Package Manager (NuGet) is responding with a "The remote server returned an error: (503) Server Unavailable" message?

Backslide

The answers below are merely workarounds. The first step to actually fixing the problem is to find what server Nuget is referring to (why oh why not print it Nuget!). 503 is a http response code. Alas, I don't know how to find out what URL Nuget is getting the error for. – Emmanuelemmeline

Answer 1

This is an obscure condition that will likely only occur on an "enterprisy" network environment. If these conditions apply you:

• you are required to access the Internet via an HTTP proxy server

• the HTTP proxy server requires a valid user ID & password (or AD authentication) to allow requests to proceed

• you've been messing with cool developer tools that were ported to Windows from a Linux/Unix environment

• the new cool tool(s) work after adding the HTTP_PROXY (or possibly HTTPS_PROXY or both) environment variable(s)

• you can access the NuGet servers from a browser without getting a 503 error

Then it's likely you broke NuGet by inadvertently invoking this configuration feature. I'm not sure exactly how the environment variable breaks NuGet but I suspect NuGet is detecting & using the http_proxy URL but sending an empty user ID & password which causes the HTTP proxy to reject the request.

Fix: remove the environment variable(s) you added and see if the cool tool can be configured to use an HTTP proxy without them.

Update: Ran into a version of this issue with the NuGet config file referenced in the "this configuration feature" link above. Open this file:

%appdata%\nuget\nuget.config

in your favorite editor. If it contains elements with http_proxy or https_proxy then removing these elements may fix the issue too.

PS: Hopefully I'll get an up vote from Colonel Panic :-)

Adnah

You sir, are are a gentlemen and a scolar! – Governance

great post - removing environment variables HTTP_PROXY and HTTPS_PROXY fixed it for me – Junitajunius

Nice one! Spent hours looking into this problem :( – Nagle

This did not work for me. I do not have those environment variables, and I tried both modifying the AppData nuget.config proxy elements and removing them. I also tried unchecking "Use a proxy server for downloads" in Options -> Source Control, and this did not seem to make a difference as well. – Sudatory

Note that if you don't need the proxy for a local(ish) nuget server. Such as a private local repo, you can use the env variable no_proxy – Night

Answer 2

If you have used the package in the past it is probably in your cache. You can add the local cache as an available package source by going into the Library Package Manager Settings under the Tools menu in Visual Studio. For Visual Studio 2012, choose Tools, Library Package Manager, Package Manager Settings, and then click on Package Sources.

In the Available package sources section, type a name like "Cache" and then in for the source, browse to %LocalAppData%\NuGet\Cache. You may need to use Windows Explorer to translate %LocalAppData%\NuGet\Cache into the full path (usually C:\Users\YourAccountName\AppData\Local\NuGet\Cache).

Once you have the Cache as an available source, you can now use the Package Manager Console (found under the View menu under Other Windows or also under the Tools menu under Library Package Manager).

From the Console (which is a PowerShell window with commandlets for NuGet) you can type "get-help NuGet" to see available commands.

Then using Get-Package, you can get a list of Package ID's. Make sure the "Package source" is set to "Cache" (or whatever you called it) and the Default project is set to the project you need manipulate, both of these are dropdowns located at the top of the Page Manager Console. You can also use the Get-Project to verify you are working against the correct project in your solution.

Finally, you can type Install-Package and when prompted enter the Package ID from the output of the Get-Package commandlet.

Backslide

Answer 3

i had also this problem, it was becouse of my network. if you have any blocking on your Internet, (like in companies internet or etc..) you may not allowed to download the nuget package.

try to download the package in another network, maybe it can help you!

Bollinger

Answer 4

Talbott's answer did not work for me, as my cache was empty. However, if you have used the package in another solution, you can copy the items you want from the "packages" folder in the other solution to a packages folder in your target solution.

If you have no packages installed in the target solution, you may need to add the following to a repositories.xml file in the packages folder:

<?xml version="1.0" encoding="utf-8"?>
<repositories>
</repositories>

After doing that, the packages appeared to be installed in my solution and I was able to add them to projects.

Additional Note: I had to use the "Manage NuGet Packages for Solution" option at the solution level to add the package to individual projects. Using Install-Package from the console still returns a 503 even though the packages is already installed in the solution.

Phane

Answer 5

You can also get this error if you are using a VPN client (e.g. Cisco AnyConnect) and you have recently renewed your VPN certificate. The issue can occur after you have updated your certificate, but before you have rebooted. A reboot resolves the issue.

Stelliform

Answer 6

It is a pretty old question, but I have just encountered the same problem. In my case it occurred because I had more than one nuget package source configured in the Visual Studio Package Manager. In my company we use NuGet to get mainstream packages and MyGet for our own stuff.

When I attempted to pull a pretty big package it failed with a 503 code and the error link looked pretty odd, it had MyGet in it istead of NuGet. Turns out Visual Studio package manager tried to pull it from another source despite having NuGet chosen as a current source. Disabling other sources and then proceeding with a download fixed it.

Hopefully it will help somebody who stumbled upon this thread just like I did.

Derron

Answer 7

Another possible reason for recieving 503: If you're using Azure DevOps feed, then NuGet packages are limited to 500 MB.

Adminicle