无法从程序集 Microsoft.Azure.Services.AppAuthentication 加载类型 Microsoft.Azure.Services.AppAuthentication.SqlAppAuthenticationProvider

Question

I am getting below errors when doing the Microsoft quickstart to setup Azure AD login for my Azure SQL:

Inner Exception 1: ArgumentException: Failed to instantiate an authentication provider with type 'Microsoft.Azure.Services.AppAuthentication.SqlAppAuthenticationProvider, Microsoft.Azure.Services.AppAuthentication' for 'ActiveDirectoryInteractive'.

Inner Exception 2: TypeLoadException: Could not load type 'Microsoft.Azure.Services.AppAuthentication.SqlAppAuthenticationProvider' from assembly 'Microsoft.Azure.Services.AppAuthentication'.

https://docs.microsoft.com/en-us/azure/app-service/app-service-web-tutorial-connect-msi

After making changes to my web config files as per the steps, it hit the error when running the web project locally.

Looks like the object SqlAppAuthenticationProvider is not implemented in the package Microsoft.Azure.Services.AppAuthentication?

Answer 1

'A few moments later...'

We had to add an extra conditional symbol in this case 'net472' to make this work.

There is a note on the Microsoft documentation that is describing the following:

'For traditional .NET Framework projects, you have to manually configure the conditional compilation symbols for the different target frameworks in Visual Studio via the project's properties pages.'

Link: https://docs.microsoft.com/en-us/dotnet/csharp/language-reference/preprocessor-directives/preprocessor-if

I found it very strange because the target framework version is already pointing to 4.7.2 but will not include the symbol net472. But never the less, after adding the symbol manually this fixes the issue.