error NU1301: Unable to load the service index for source

Steve Ellwood
2 min readMar 8


I’ve been battling with entity framework to try to get a database migrated from a local instance to Azure. The rest of that story is for another day, however I am creating a .net 6 application and wanted to run the ef commands from the command line. This is the dotnet tool for using entity framework.

When I tried to install using

dotnet tool install --global dotnet-ef

I got the error —

error NU1301: Unable to load the service index for source ...
The tool package could not be restored.
Tool 'ef' failed to install. This failure may have been caused by:

* You are attempting to install a preview release and did not use the --version option to specify the version.
* A package by this name was found, but it was not a .NET tool.
* The required NuGet feed cannot be accessed, perhaps because of an Internet connection problem.
* You mistyped the name of the tool.

For more reasons, including package naming enforcement, visit

The link provided didn’t work for me, it just took me to Bing

Fortunately the solution in this case was very simple — the gist of it is that you need to delete the following file


So I opened up file explorer and put just the path part in but it didn’t like it for some reason, what it did let me do was open %AppData%\Roaming\ and then search using file explorer for Nuget.config. in my case it came up with a single file which I deleted and then the tool installed as expected.



Steve Ellwood

Senior Integrations Officer at Doncaster Council Any views expressed are entirely my own.