Unable to connect to iis express

Possible cause: launchSettings.json

• File was corrupt or incorrect
• File was changed and that caused failure

Solution:

• Close Visual Studio
• Go to project folder > properties > Delete launchSettings.json
• Open Visual studio > run the project
• Coutesy: Comment by “Quinton Smith” in StackOverflow answer: https://stackoverflow.com/a/36801686/4802664

No database provider has been configured for this DbContext

• Check: services.AddDbContext<ApplicationDbContext>(options => ... ) in Startup.cs
• Check: public ApplicationDbContext(DbContextOptions<ApplicationDbContext> options) : base(options){} in the DbContext class
• Check that there is no parameterless public constructor in DbContext class (delete parameterless public constructor)

Other probable reason: https://stackoverflow.com/questions/38338475/no-database-provider-has-been-configured-for-this-dbcontext-on-signinmanager-p

HTTP Error 500.30 - ANCM In-Process Start Failure

Possible Cuase and solution 1

• Question: https://stackoverflow.com/questions/53811569/http-error-500-30-ancm-in-process-start-failure
• Worked answer: https://stackoverflow.com/a/59390437/4802664

Possible Cuase and solution 2

• If you are accessing KeyVault as code shown below
• Currently logged in user in Visual Studion does not have access right to the secret (KeyVault access policy)

Program.cs

// CreateHostBuilder()

var builtConfig = config.Build();

var keyVaultName = builtConfig[builtConfig["KeyVaultNameIdentifierKey"]];
var secretClient = new SecretClient(new Uri($"https://{keyVaultName}.vault.azure.net/"), new DefaultAzureCredential());

config.AddAzureKeyVault(secretClient, new KeyVaultSecretManager());

// ... ... ...

Solution

• Got to KeyVault
• Add access policy for currently logged in user (the user who is currently logged in to Visual Studio)

InvalidOperationException: The ConfigureServices method must either be parameterless or take only one parameter of type IServiceCollection

Reason: you tried to add parameter to ConfigureServices for DI i.e. IWebHostEnvironment env

// ... ... ...

public void ConfigureServices(IServiceCollection services, IWebHostEnvironment env)
{
    services.AddRazorPages();
    services.AddServerSideBlazor();

    if (env.IsDevelopment())
    {

    }
}

Splution: remove added parameter and use constructor injection

// ... ... ...

public IWebHostEnvironment Environment { get; set; }

public Startup(IConfiguration configuration, IWebHostEnvironment env) // constructor injection
{
    Configuration = configuration;
    Environment = env;
}

public void ConfigureServices(IServiceCollection services)
{
    services.AddRazorPages();
    services.AddServerSideBlazor();

    if (Environment.IsDevelopment())
    {

    }

}