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Auth0.AuthenticationApi not getting installed in a .Net web application.



There is a requirement in my project where we have to integrate Auth0 with our legacy .Net application but when I try to install “Auth0.AuthenticationApi” through Package manager console the below error comes out:

“Could not install package ‘Auth0.AuthenticationApi 4.1.0’. You are trying to install this package into a project that targets ‘.NETFramework,Version=v4.0’, but the package does not contain any assembly references or content files that are compatible with that framework. For more information, contact the package author.”

I tried installing lower version also but without any success. Is there any workaround around this?

Thanks in advance.

I am using VS 2017 Pro.


Yes, the Auth0.AuthenticationApi NuGet package supports .NET Standard 1.1 which means you need to use at least .NET Framework 4.5

For more information see

The reason for this is that the library uses async/await, which is only supported from .NET Framework 4.5 onwards.


Thanks jerrie for the quick response. I guess the only option left now is to upgrade to .NET 4.5.