Scaffolding exceptions for Blazor Web App

[guardrex]

File a bug

Include your code

Steps to reproduce are basic use of the scaffolder without any custom code ...

1. Create a new BWA with Individual Accounts.
2. In Solution Explorer, right-click Add > New Scaffolded Item.
3. Select Identity > Blazor Identity. Select the Add button.
4. On the Add Blazor Identity step, override the file for Pages\Manage\EnableAuthenticator in the list of pages. Select the app's DBContext class. Select the Add button.

Exception

Include stack traces

Stack Trace:

Finding the generator 'blazor-identity'...
Running the generator 'blazor-identity'...
No database provider found. Using 'SqlServer' by default for new DbContext creation!
Using 'SQL Server' by default!
Empty or invalid namespace provided, using default namespace.
Added Blazor identity file : C:\Users\xxx\Desktop\BWA80IdentityDELETEME\BWA80Identity\BWA80Identity\Components\Account\Pages\Manage\EnableAuthenticator.razor
Modified C:\Users\xxx\Desktop\BWA80IdentityDELETEME\BWA80Identity\BWA80Identity\Program.cs.
Value cannot be null. (Parameter 'path')
   at Microsoft.VisualStudio.Web.CodeGeneration.ActionInvoker.<BuildCommandLine>b__6_0()
   at Microsoft.Extensions.CommandLineUtils.CommandLineApplication.Execute(String[] args)
   at Microsoft.VisualStudio.Web.CodeGeneration.ActionInvoker.Execute(String[] args)
   at Microsoft.VisualStudio.Web.CodeGeneration.CodeGenCommand.Execute(String[] args)

Result

It seems like the scaffolder is working. The EnableAuthenticator component is present. However, I only ask for the EnableAuthenticator component, but the scaffolder is giving the app all of them ...

Anyway ... kill the app and restart it ... here is the next exception during migrations on first run ...

fail: Microsoft.EntityFrameworkCore.Database.Connection[20004]
      An error occurred using the connection to database 'aspnet-BWA80Identity-9e2925d7-47fc-4af2-93c4-fb04266c4f5d' on server '(localdb)\mssqllocaldb'.
fail: Microsoft.EntityFrameworkCore.Query[10100]
      An exception occurred while iterating over the results of a query for context type 'BWA80Identity.Data.ApplicationDbContext'.
      System.InvalidOperationException: An exception has been raised that is likely due to a transient failure. Consider enabling transient error resiliency by adding 'EnableRetryOnFailure' to the 'UseSqlServer' call.
       ---> Microsoft.Data.SqlClient.SqlException (0x80131904): Cannot open database "aspnet-BWA80Identity-9e2925d7-47fc-4af2-93c4-fb04266c4f5d" requested by the login. The login failed.
      Login failed for user 'xxx'.
         at Microsoft.Data.SqlClient.SqlInternalConnection.OnError(SqlException exception, Boolean breakConnection, Action`1 wrapCloseInAction)
         at Microsoft.Data.SqlClient.TdsParser.ThrowExceptionAndWarning(TdsParserStateObject stateObj, Boolean callerHasConnectionLock, Boolean asyncClose)
         at Microsoft.Data.SqlClient.TdsParser.TryRun(RunBehavior runBehavior, SqlCommand cmdHandler, SqlDataReader dataStream, BulkCopySimpleResultSet bulkCopyHandler, TdsParserStateObject stateObj, Boolean& dataReady)
         at Microsoft.Data.SqlClient.TdsParser.Run(RunBehavior runBehavior, SqlCommand cmdHandler, SqlDataReader dataStream, BulkCopySimpleResultSet bulkCopyHandler, TdsParserStateObject stateObj)
         at Microsoft.Data.SqlClient.SqlInternalConnectionTds.CompleteLogin(Boolean enlistOK)
         at Microsoft.Data.SqlClient.SqlInternalConnectionTds.AttemptOneLogin(ServerInfo serverInfo, String newPassword, SecureString newSecurePassword, Boolean ignoreSniOpenTimeout, TimeoutTimer timeout, Boolean withFailover)
         at Microsoft.Data.SqlClient.SqlInternalConnectionTds.LoginNoFailover(ServerInfo serverInfo, String newPassword, SecureString newSecurePassword, Boolean redirectedUserInstance, SqlConnectionString connectionOptions, SqlCredential credential, TimeoutTimer timeout)
         at Microsoft.Data.SqlClient.SqlInternalConnectionTds.OpenLoginEnlist(TimeoutTimer timeout, SqlConnectionString connectionOptions, SqlCredential credential, String newPassword, SecureString newSecurePassword, Boolean redirectedUserInstance)
         at Microsoft.Data.SqlClient.SqlInternalConnectionTds..ctor(DbConnectionPoolIdentity identity, SqlConnectionString connectionOptions, SqlCredential credential, Object providerInfo, String newPassword, SecureString newSecurePassword, Boolean redirectedUserInstance, SqlConnectionString userConnectionOptions, SessionData reconnectSessionData, Boolean applyTransientFaultHandling, String accessToken, DbConnectionPool pool)
         at Microsoft.Data.SqlClient.SqlConnectionFactory.CreateConnection(DbConnectionOptions options, DbConnectionPoolKey poolKey, Object poolGroupProviderInfo, DbConnectionPool pool, DbConnection owningConnection, DbConnectionOptions userOptions)
         at Microsoft.Data.ProviderBase.DbConnectionFactory.CreatePooledConnection(DbConnectionPool pool, DbConnection owningObject, DbConnectionOptions options, DbConnectionPoolKey poolKey, DbConnectionOptions userOptions)
         at Microsoft.Data.ProviderBase.DbConnectionPool.CreateObject(DbConnection owningObject, DbConnectionOptions userOptions, DbConnectionInternal oldConnection)
         at Microsoft.Data.ProviderBase.DbConnectionPool.UserCreateRequest(DbConnection owningObject, DbConnectionOptions userOptions, DbConnectionInternal oldConnection)
         at Microsoft.Data.ProviderBase.DbConnectionPool.TryGetConnection(DbConnection owningObject, UInt32 waitForMultipleObjectsTimeout, Boolean allowCreate, Boolean onlyOneCheckConnection, DbConnectionOptions userOptions, DbConnectionInternal& connection)
         at Microsoft.Data.ProviderBase.DbConnectionPool.WaitForPendingOpen()
      --- End of stack trace from previous location ---
         at Microsoft.EntityFrameworkCore.Storage.RelationalConnection.OpenInternalAsync(Boolean errorsExpected, CancellationToken cancellationToken)
         at Microsoft.EntityFrameworkCore.Storage.RelationalConnection.OpenInternalAsync(Boolean errorsExpected, CancellationToken cancellationToken)
         at Microsoft.EntityFrameworkCore.Storage.RelationalConnection.OpenAsync(CancellationToken cancellationToken, Boolean errorsExpected)
         at Microsoft.EntityFrameworkCore.Storage.RelationalCommand.ExecuteReaderAsync(RelationalCommandParameterObject parameterObject, CancellationToken cancellationToken)
         at Microsoft.EntityFrameworkCore.Query.Internal.SingleQueryingEnumerable`1.AsyncEnumerator.InitializeReaderAsync(AsyncEnumerator enumerator, CancellationToken cancellationToken)
         at Microsoft.EntityFrameworkCore.SqlServer.Storage.Internal.SqlServerExecutionStrategy.ExecuteAsync[TState,TResult](TState state, Func`4 operation, Func`4 verifySucceeded, CancellationToken cancellationToken)
      ClientConnectionId:cfed530f-488e-47e5-839f-f6628ed1def6
      Error Number:4060,State:1,Class:11
         --- End of inner exception stack trace ---
         at Microsoft.EntityFrameworkCore.SqlServer.Storage.Internal.SqlServerExecutionStrategy.ExecuteAsync[TState,TResult](TState state, Func`4 operation, Func`4 verifySucceeded, CancellationToken cancellationToken)
         at Microsoft.EntityFrameworkCore.Query.Internal.SingleQueryingEnumerable`1.AsyncEnumerator.MoveNextAsync()
      System.InvalidOperationException: An exception has been raised that is likely due to a transient failure. Consider enabling transient error resiliency by adding 'EnableRetryOnFailure' to the 'UseSqlServer' call.
       ---> Microsoft.Data.SqlClient.SqlException (0x80131904): Cannot open database "aspnet-BWA80Identity-9e2925d7-47fc-4af2-93c4-fb04266c4f5d" requested by the login. The login failed.
      Login failed for user 'XXXXXX'.
         at Microsoft.Data.SqlClient.SqlInternalConnection.OnError(SqlException exception, Boolean breakConnection, Action`1 wrapCloseInAction)
         at Microsoft.Data.SqlClient.TdsParser.ThrowExceptionAndWarning(TdsParserStateObject stateObj, Boolean callerHasConnectionLock, Boolean asyncClose)
         at Microsoft.Data.SqlClient.TdsParser.TryRun(RunBehavior runBehavior, SqlCommand cmdHandler, SqlDataReader dataStream, BulkCopySimpleResultSet bulkCopyHandler, TdsParserStateObject stateObj, Boolean& dataReady)
         at Microsoft.Data.SqlClient.TdsParser.Run(RunBehavior runBehavior, SqlCommand cmdHandler, SqlDataReader dataStream, BulkCopySimpleResultSet bulkCopyHandler, TdsParserStateObject stateObj)
         at Microsoft.Data.SqlClient.SqlInternalConnectionTds.CompleteLogin(Boolean enlistOK)
         at Microsoft.Data.SqlClient.SqlInternalConnectionTds.AttemptOneLogin(ServerInfo serverInfo, String newPassword, SecureString newSecurePassword, Boolean ignoreSniOpenTimeout, TimeoutTimer timeout, Boolean withFailover)
         at Microsoft.Data.SqlClient.SqlInternalConnectionTds.LoginNoFailover(ServerInfo serverInfo, String newPassword, SecureString newSecurePassword, Boolean redirectedUserInstance, SqlConnectionString connectionOptions, SqlCredential credential, TimeoutTimer timeout)
         at Microsoft.Data.SqlClient.SqlInternalConnectionTds.OpenLoginEnlist(TimeoutTimer timeout, SqlConnectionString connectionOptions, SqlCredential credential, String newPassword, SecureString newSecurePassword, Boolean redirectedUserInstance)
         at Microsoft.Data.SqlClient.SqlInternalConnectionTds..ctor(DbConnectionPoolIdentity identity, SqlConnectionString connectionOptions, SqlCredential credential, Object providerInfo, String newPassword, SecureString newSecurePassword, Boolean redirectedUserInstance, SqlConnectionString userConnectionOptions, SessionData reconnectSessionData, Boolean applyTransientFaultHandling, String accessToken, DbConnectionPool pool)
         at Microsoft.Data.SqlClient.SqlConnectionFactory.CreateConnection(DbConnectionOptions options, DbConnectionPoolKey poolKey, Object poolGroupProviderInfo, DbConnectionPool pool, DbConnection owningConnection, DbConnectionOptions userOptions)
         at Microsoft.Data.ProviderBase.DbConnectionFactory.CreatePooledConnection(DbConnectionPool pool, DbConnection owningObject, DbConnectionOptions options, DbConnectionPoolKey poolKey, DbConnectionOptions userOptions)
         at Microsoft.Data.ProviderBase.DbConnectionPool.CreateObject(DbConnection owningObject, DbConnectionOptions userOptions, DbConnectionInternal oldConnection)
         at Microsoft.Data.ProviderBase.DbConnectionPool.UserCreateRequest(DbConnection owningObject, DbConnectionOptions userOptions, DbConnectionInternal oldConnection)
         at Microsoft.Data.ProviderBase.DbConnectionPool.TryGetConnection(DbConnection owningObject, UInt32 waitForMultipleObjectsTimeout, Boolean allowCreate, Boolean onlyOneCheckConnection, DbConnectionOptions userOptions, DbConnectionInternal& connection)
         at Microsoft.Data.ProviderBase.DbConnectionPool.WaitForPendingOpen()
      --- End of stack trace from previous location ---
         at Microsoft.EntityFrameworkCore.Storage.RelationalConnection.OpenInternalAsync(Boolean errorsExpected, CancellationToken cancellationToken)
         at Microsoft.EntityFrameworkCore.Storage.RelationalConnection.OpenInternalAsync(Boolean errorsExpected, CancellationToken cancellationToken)
         at Microsoft.EntityFrameworkCore.Storage.RelationalConnection.OpenAsync(CancellationToken cancellationToken, Boolean errorsExpected)
         at Microsoft.EntityFrameworkCore.Storage.RelationalCommand.ExecuteReaderAsync(RelationalCommandParameterObject parameterObject, CancellationToken cancellationToken)
         at Microsoft.EntityFrameworkCore.Query.Internal.SingleQueryingEnumerable`1.AsyncEnumerator.InitializeReaderAsync(AsyncEnumerator enumerator, CancellationToken cancellationToken)
         at Microsoft.EntityFrameworkCore.SqlServer.Storage.Internal.SqlServerExecutionStrategy.ExecuteAsync[TState,TResult](TState state, Func`4 operation, Func`4 verifySucceeded, CancellationToken cancellationToken)
      ClientConnectionId:cfed530f-488e-47e5-839f-f6628ed1def6
      Error Number:4060,State:1,Class:11
         --- End of inner exception stack trace ---
         at Microsoft.EntityFrameworkCore.SqlServer.Storage.Internal.SqlServerExecutionStrategy.ExecuteAsync[TState,TResult](TState state, Func`4 operation, Func`4 verifySucceeded, CancellationToken cancellationToken)
         at Microsoft.EntityFrameworkCore.Query.Internal.SingleQueryingEnumerable`1.AsyncEnumerator.MoveNextAsync()

I then killed the app and restarted it again ... everything seems to work. I'm able to register a test user, sign them in, and access the authenticator page ...

Include provider and version information

Microsoft.VisualStudio.Web.CodeGeneration.Design/Microsoft.DotNet.MSIdentity version: 8.0.2
Target framework: .NET 8.0
Operating system: Windows
IDE: Visual Studio 17.10.0 Preview 1.0

[Ksdmg]

I'm facing the same issue.
Target framework: .NET 8.0
Operating system: Windows
IDE: Visual Studio 17.10.1

[elbec]

@Ksdmg: Do you found a solution? I have the same issuce in .NET 8.0

[constructor]

I ran into this issue today.
What is the precise cause?
Anyone got a solution/work around?
@Ksdmg @elbec

Using database provider 'Npgsql.EntityFrameworkCore.PostgreSQL'!
Value cannot be null. (Parameter 'path')
at Microsoft.VisualStudio.Web.CodeGeneration.ActionInvoker.b__6_0()
at Microsoft.Extensions.CommandLineUtils.CommandLineApplication.Execute(String[] args)
at Microsoft.VisualStudio.Web.CodeGeneration.ActionInvoker.Execute(String[] args)
at Microsoft.VisualStudio.Web.CodeGeneration.CodeGenCommand.Execute(String[] args)

[elbec]

Hello, yes i found yesterday a workaround for me. It did not work for me directly in Visual Stuido. But when i run in project folder with cmd dotnet aspnet-codegenerator identity. Then all files were created without an error!

[constructor]

I have a IDesignTimeDbContextFactory, that creates a DbContext. I have checked this by launching a debugger during scaffolding. When the IDesignTimeDbContextFactory returns the DbContext, I still get:

Using database provider 'Npgsql.EntityFrameworkCore.PostgreSQL'!
Value cannot be null. (Parameter 'path')
at Microsoft.VisualStudio.Web.CodeGeneration.ActionInvoker.b__6_0()
at Microsoft.Extensions.CommandLineUtils.CommandLineApplication.Execute(String[] args)
at Microsoft.VisualStudio.Web.CodeGeneration.ActionInvoker.Execute(String[] args)
at Microsoft.VisualStudio.Web.CodeGeneration.CodeGenCommand.Execute(String[] args)

Is there any more information on this error? What is the Parameter 'path'?

[constructor]

In the very latest VS, with all updates, in my project I have tried:

1. EF Migrations, and they work perfectly.
2. RtClick > Add >New Scaffold Item > Razor Pages > Razor Pages using Entity Framwork (CRUD)
   This works perfectly.
3. RtClick > Add >New Scaffold Item > Razor Component > Razor Components using Entity Framwork (CRUD)
   I get the output:

Building project ...
Finding the generator 'blazor'...
Running the generator 'blazor'...
Attempting to figure out the EntityFramework metadata for the model and DbContext: 'RadProjectItem'

Using database provider 'Npgsql.EntityFrameworkCore.PostgreSQL'!

Value cannot be null. (Parameter 'path')
at Microsoft.VisualStudio.Web.CodeGeneration.ActionInvoker.b__6_0()
at Microsoft.Extensions.CommandLineUtils.CommandLineApplication.Execute(String[] args)
at Microsoft.VisualStudio.Web.CodeGeneration.ActionInvoker.Execute(String[] args)
at Microsoft.VisualStudio.Web.CodeGeneration.CodeGenCommand.Execute(String[] args)

There is no information anywhere to be found.

[constructor]

The App.razor file must exist in order for scaffolding to work. I am not using the App.razor file, therefore I removed it. Adding it back into the project makes the scaffolding operation complete without error.

[Dennis951]

For me it worked to add back the NavMenu. I looked up what got changed in a new project. Those were these files: