Application can't scaffold items

Question

I created an MVC 5 application in VS 2013 Professional and then used EF 6.1 code first with an existing DB on SQL Server Express. When I try to create the views I’m using the “New scaffolded item…” then selecting the “MVC 5 controller with views, using Entity Framework.” I select the model and context classes and click OK. Then the following error message appears and no code is created. I’ve uninstalled EF Power Tools with the same error.

Error

There was an error running the selected code generator: ‘Exception has been thrown by the target of an invocation.’

I've also tried uninstalling/reinstalling VS 2013 and SQL Server with no changes.

Any other ideas about what might cause this error?

The only idea I have is that some references are not pointing the appropriate version. That's when I see those inexplicable errors. — TheNorthWes, May 16 '14 at 16:53
I have this same error as well. As a workaround, I was able to comment out any fluent api code in my `DbContext.OnModelCreating()` method, and was able to scaffold out the controller. Then I uncommented the offending lines and went on my merry way. — Albert Bori, May 17 '14 at 21:55
If you are having this issue could you please email us at joostden@microsoft.com or sayedha@microsoft.com. — Sayed Ibrahim Hashimi, Jun 05 '14 at 17:11
@AlbertBori any idea on what the real cause of this issue is? I also have this problem and commenting out `.AddFromAssembly(Assembly.GetExecutingAssembly())` fixes it for me — Eonasdan, Jun 30 '14 at 19:53
Anyone who is trying to implement @AlbertBori solution, first build the project where your fluent api is in and then scaffold out your controller — Hernan Demczuk, Mar 23 '16 at 22:11

score 42 · Answer 1 · answered Jul 22 '14 at 10:01

42

In my case I moved my connection strings out of the Web.config to

<connectionStrings configSource="ConnectionStrings.config"/>

that when I started getting the error when I was trying to scaffold.

There was an error running the selected code generator: ‘Exception has been thrown by the target of an invocation.’

Moving my connection strings back to the Web.config solved my issue.

answered Jul 22 '14 at 10:01

Developer SPM

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4

had duplicate connection string entries in my web.config – David McSpadden Aug 06 '15 at 20:55
3

I had declared the connection strings before the configSections node. So the scaffolder was not able to find EF. – Hemant Oct 05 '15 at 13:16
2

BOOOO MSFT. This was my issue. – Andy V Mar 29 '16 at 20:27
I too had the connectionstring before the ConfigSections. Moving it after the ConfigSections solved it for me. Cheers !!! – Jackson Lopes Jun 19 '17 at 06:16
@DavidMcSpadden bro, you sould post your comment as a new response. After hours I solved my error because of you. Thanks! – Phi Aug 24 '17 at 18:52
Yeah, that was it! Thanks! But how to separate web.config into 2 files without this pain? – Tsagana Nokhaeva Jan 30 '18 at 09:59

score 16 · Accepted Answer · answered May 28 '14 at 07:46

16

I had this problem too, I solved the problem by calling the base.onModelCreating in my DB context

base.OnModelCreating(modelBuilder);

answered May 28 '14 at 07:46

Mhand7

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This fixed the problem for me. Put this line of code at the very end of the OnModelCreating method after all the entities have bee configured. VS2013 Update 4 – Aaron May 29 '15 at 17:14
2

I have this line in my code to begin with, but I am still having the error when adding new scaffolded items. Using VS 2013 Update 5 and SQL Server Express 2012 and following the tutorial at http://www.asp.net/mvc/overview/getting-started/getting-started-with-ef-using-mvc/creating-an-entity-framework-data-model-for-an-asp-net-mvc-application – Stack0verflow Nov 05 '15 at 20:20

score 14 · Answer 3 · edited Sep 06 '17 at 07:11

14

I had faced the same problem while creating controller using scaffold with 'ASP.NET MVC5 using views with Entity Framework'

The problem was because I provided <connectionStrings> tag before <configSections> in web.config. setting <connectionStrings> after <configSections> resolved the issue.

I guess, while scaffolding, ASP.NET MVC want to resolve the Entity Framework first, then the connection string, as I have provided connection string earlier so that after resolving the Entity Framework version it could not find the connection string so it thrown invocation problem.

edited Sep 06 '17 at 07:11

marc_s

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answered Mar 01 '16 at 17:56

Shirajul Mamun

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I have my context and model classes in a separate project and this worked for me too. Thanks. – Tahir Hassan May 01 '18 at 14:21
This Solved the problem for me in VS 2019 ASP.NET (Full Framework) MVC Application. Using Entityframework 6. – Avinash Barnwal Jul 26 '20 at 16:57

score 13 · Answer 4 · edited Dec 13 '16 at 19:08

13

This solved the issue for me,

Adding throwIfV1Schema: false to base of DbContext

As so:

public MyDbContext() : base("ConectionStringName", throwIfV1Schema: false) { }

edited Dec 13 '16 at 19:08

Alex C

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answered Feb 25 '15 at 16:08

Rewdiz

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Don't forget to rebuild after doing this! – lordstyx Mar 01 '17 at 20:21

Ashok kumar · Answer 5 · 2014-10-13T14:08:54.717

10

Late reply; but, I am posting this answers with the hope that somebody can use this answer to solve their problem.

For some reason, if your program CANNOT read connectionString information (either from web.config or from other means) then, this error will be thrown.

Make sure that valid connectionString information is being retrieved properly without any problem.

edited Oct 13 '14 at 14:08

answered Oct 13 '14 at 14:03

Ashok kumar

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score 6 · Answer 6 · answered Jun 11 '14 at 03:11

I had the same error message. I tried adding a new Data context class from the Add Controller dialog, and then I got a different error:

There was an error running the selected code generator:
'Sections must only appear once per config file. See the help topic
<locations> for exceptions.

It turns out that I had two <connectionStrings> elements in my web.config file. (I had pasted one from the app.config of the class library that contained my Entity Framework model.)

I often pride myself on not doing stupid things. This, today, was one of a few. Good catch and call. — user4593252, Jul 10 '16 at 01:32

score 5 · Answer 7 · answered Jun 09 '14 at 21:18

5

In my case, I had to revert my DBContext constructor to just using a static connection string, as defined in web.config

Scaffolding did not work when I used a dynamically created connection string.

public MyContext() : base("name=MyContext") { }

answered Jun 09 '14 at 21:18

tr3v

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score 5 · Answer 8 · edited Jan 02 '18 at 20:23

5

I had the same problem where it wouldn't add scaffold items it seems that uninstalling entity-framework through the nuget package manager console works

To Run Package Manager Console :

Tools -> NuGet Package Manager -> Package Manager Console

To Remove:

UnInstall-Package EntityFramework

To Reinstall:

Install-Package EntityFramework

Or in one command:

Update-Package -reinstall EntityFramework

I hope this can help someone as it took me a while to come to this.

edited Jan 02 '18 at 20:23

M. Colby

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answered Sep 16 '14 at 20:11

Enzero

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this worked for me to, must be some configuration change it makes (but where, in the solution or one of the config files?) – sam starobin Feb 19 '15 at 22:39
@JosephCasey I don't know but you must have some kind of dependency somewhere which is stopping you from uninstalling check what packages you have installed and see what dependencies they have. You will have to uninstall them first before removing EntityFramework. – Enzero May 04 '15 at 14:24
@JosephCasey are you by chance using the beta version of Entity Frameworks since that does have a dependency (EntityFramework.Commands). It might be better to just use the current version at date being 6.1.3. – Enzero May 05 '15 at 10:14
I have EF 6.1.3. I can try to check it later. I think the bigger problem was my out-of-date approach. – Joseph Casey May 05 '15 at 13:02

score 3 · Answer 9 · answered May 19 '14 at 18:11

3

This may help resolve your error.

In my OnModelCreating i was doing this for each entity:

modelBuilder.Configurations.Add(new EntityTypeConfiguration<EntityModel>);

When i changed it to the following i stopped getting the error you are receiving.

modelBuilder.Entity<EntityModel>();

answered May 19 '14 at 18:11

chicken

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I had the exact same problem, for some reason it doesn't like the EntityTypeConfiguration class, thanks! – Gabriel Sadaka Aug 09 '15 at 06:44

score 3 · Answer 10 · answered Nov 24 '15 at 16:20

I tried most of the above without luck.

What finally worked was:

Delete the previously dynamically created string entry
Delete my model (keeping all controllers and views)
Recreate the ADO.NET Entity Data Model - using the same name, creating a new connection string entry with the same name as before

Then everything worked again, minus 3 hours of development time.

re-add (from a backup) all of my property attributes to the table/entity classes

Seems to have something to do with the dynamically created connection string and the model. Would appreciate any thoughts on what could have happened.

score 2 · Answer 11 · answered Aug 05 '14 at 21:37

In my case, I solved the issue with the connection string in the web.config.

Previuos the issue I has <connectionStrings configSource="Configs\ConnectionString.config"/>

and I doesnt know why, but vs cant connect to the database and fail.

after the change

<connectionStrings> <add name="UIBuilderContext" connectionString="metadata=res:/ ..... " /> </connectionStrings>

and it works

DJ. · Answer 12 · 2015-02-20T17:18:42.037

2

My solution was as simple as changing back the connection string name in my Web Config to DefaultConnection. Even though my dbContext has another name!

Took me 2 hours to find out this nonsense!

edited Feb 20 '15 at 17:18

answered Feb 20 '15 at 16:39

DJ.

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score 2 · Answer 13 · edited Mar 13 '15 at 06:41

It seems a problem of connecting setting / inconsistent entry in via Web.config. To fix this issue , follow below steps:

Remove connection related information (staring with <connectionStrings> from Web.config and remove models generated so far.

Now generate the model and it will add fresh connection entry in Web.config file. Once model is generated, build the solution then start doing Scaffolding controlled. it will work.

Greg Veres · Answer 14 · 2016-02-24T20:13:38.730

I ran into this problem too using VS 2015. I tried all the other solutions here to no success. It turned out that my connection string (although formed exactly how MS tells us to form it) needed double \ to work properly.

Here is what it was that was NOT working:

<add name="DefaultConnection" connectionString="Data Source=(LocalDb)\V11.0;AttachDbFilename=|DataDirectory|\SquashSpiderDB.mdf;Initial Catalog=SquashSpiderDB;Integrated Security=True" providerName="System.Data.SqlClient" />

and here is what I changed it to in order to get the code generator to work:

<add name="DefaultConnection" connectionString="Data Source=(LocalDb)\\V11.0;AttachDbFilename=|DataDirectory|\SquashSpiderDB.mdf;Initial Catalog=SquashSpiderDB;Integrated Security=True" providerName="System.Data.SqlClient" />

Notice the double \ characters in front of V11.0 and the database name.

Hope this saves somebody else some time.

UPDATE

This gets the code generation to work, but then the app won't run because the \V11.0 isn't a valid connection string. This looks to me like MS has a bug in their code generation when it parses the connection string. I had to change it back to a single \ after I ran the code generation to get the app working again.

UPDATE 2

After some more digging by my partner, we found out that what was really screwing up code generation was the fact that we had changed the "Initial Catalog" field. When the project was created by the Wizard, it automatically set the Initial Catalog to aspnet--. We had then changed this Initial Catalog field to be DB. This worked great for the application running. It could get to the database just fine. But for some reason this screws up the code scaffolding generation. By putting the Initial Catalog back to what it was before (the aspnet--, the scaffolding started to work again (without needing the \V11.0).

Hope that helps somebody in the future.

To me, your answer before your two updates solved the issue. I just used double backslashes (\\\) in the place where single backslash (\\) was used, and it finally worked thank you. — yibe, Aug 11 '18 at 14:47

score 2 · Answer 15 · answered Sep 03 '16 at 18:50

2

Check relationships between entities or other model design problem. For testing, create new class model without no relationship and use Scaffold to generate controllers and views. Works for me.

answered Sep 03 '16 at 18:50

FVVID

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The simple advice "check relationships" led me in the right direction. In my case I had a bad [ForeignKey()] decorator on an EF class. Once that was fixed, problem solved. – Eric Sassaman Aug 01 '18 at 20:39

score 1 · Answer 16 · answered May 20 '14 at 11:28

1

I was getting the same error when I made some changes to my model .. Only way I was able to resolve was 1) stop/kill the process 2) clean solution and rebuild the solution

answered May 20 '14 at 11:28

user3507981

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score 1 · Answer 17 · answered Mar 06 '15 at 23:12

If by any chance you are following "Getting Started with Entity Framework 6 Code First using MVC 5" by Tom Dykstra.

I doubled check everything and my connection string is perfect. What I failed to realize was I copied another set of appSettings which I already have. Look below

  <appSettings>
    <add key="webpages:Version" value="3.0.0.0" />
    <add key="webpages:Enabled" value="false" />
    <add key="ClientValidationEnabled" value="true" />
    <add key="UnobtrusiveJavaScriptEnabled" value="true" />
  </appSettings>

My advice is to check every inch of Web.config and I'm sure that is the culprit.

score 1 · Answer 18 · answered Mar 15 '15 at 13:23

In my case NuGet added the following provider to the web.config:

<provider invariantName="System.Data.SqlServerCe.4.0" type="System.Data.Entity.SqlServerCompact.SqlCeProviderServices, EntityFramework.SqlServerCompact"/>

When I changed the provider to

<provider invariantName="System.Data.SqlClient" type="System.Data.Entity.SqlServer.SqlProviderServices, EntityFramework.SqlServer"/>

It solved the problem (costed me about 5 hours though to figure it out :-( )

score 1 · Answer 19 · edited Feb 04 '16 at 16:01

1

I Had the same error. Here are the two things I did to fix the problem:

Added name to base in my context: base("name=connectionstringname")
I made a mistake in myconnection string and fixed it.

edited Feb 04 '16 at 16:01

Kmeixner

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answered Feb 04 '16 at 15:13

Reonbs

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score 1 · Answer 20 · answered Mar 22 '17 at 11:41

It is (I'm 99% positive) a connection string issue. Once i fixed the issue in Web.Config the error went away. I was using DB first, in another project and once I copied the DB first connection string from the App.config into the web.config (using the same name) it worked as expected.

score 0 · Answer 21 · answered Feb 04 '16 at 23:54

Using Visual Studio 2015

Upgraded mysql server and in the process the mysql for visual studios was upgraded from 6.9.7 to 6.9.8

In my web config there was still a reference to the old 6.9.7 version

Here is my git diff that solved the issue:

-      <provider invariantName="MySql.Data.MySqlClient" type="MySql.Data.MySqlClient.MySqlProviderServices,MySql.Data.Entity.EF6,Version=6.9.7.0,Culture=neutral,PublicKeyToken=c5687fc88969c44d"></provider>
+      <provider invariantName="MySql.Data.MySqlClient" type="MySql.Data.MySqlClient.MySqlProviderServices,MySql.Data.Entity.EF6,Version=6.9.8.0,Culture=neutral,PublicKeyToken=c5687fc88969c44d"></provider>

score 0 · Answer 22 · answered Jun 08 '17 at 17:18

I realize this question is old now, but I thought I'd post what solved my issue in case it helps anyone later on. In my case, it was a combination of several things mentioned in other answers. To secure my connection string I had...

Moved the connection string out of the Web.config file
Moved the server name and password to a separate file referenced in the AppSettings portion of Web.config
Used a SqlConnectionStringBuilder to put the elements together and then pass it to my context class constructor

After doing this, I was unable to create any more controllers. To fix the issue, I had to ...

Put the complete connection string back in Web.config AND remove the reference to the external connection string file
Add a parameterless constructor to my context class and give it the name of my connectionString like this: public contextClass() : base("name=connectionStringName") { }
Rebuild the solution, and create the controller again, and it worked!

score 0 · Answer 23 · answered Jun 27 '17 at 14:14

everyone. I know I'm a little late, but I think that is still valid to share my experience with this problem.

I faced this message in two projects and in both cases the problem was with the connection string.

In the first case it was "InitialCatalog" instead of "Initial Catalog" (separated).

In the second case the server name (Data Source param) was wrong.

I hope it helps.

Best regards.

score 0 · Answer 24 · answered Jul 31 '17 at 02:33

For some reason when I comment the oracle.manageddataaccess.client section out between <configSections> in web.config, it worked. (VS 2015 and ODT 12)

<configSections>   
    <section name="entityFramework" type" />
    <!-- For more information on Entity Framework configuration, visit http://go.microsoft.com/fwlink/?LinkID=237468 -->
    <!--<section name="oracle.manageddataaccess.client" />-->
</configSections>

score 0 · Answer 25 · answered Aug 04 '17 at 15:01

In my case, the problem was caused by an external app settings file:

<appSettings configSource="appSettings.config" />

Bringing the app settings back into the web.config file resolved the issue.

<appSettings>
    <add key="webpages:Version" value="3.0.0.0" />
    <add key="webpages:Enabled" value="false" />
    <add key="ClientValidationEnabled" value="true" />
    <add key="UnobtrusiveJavaScriptEnabled" value="true" />
</appSettings>

score 0 · Answer 26 · answered Apr 25 '19 at 21:09

I had this:

<appSettings configSource="App_Config\Server\AppSettings.config" />
<connectionStrings configSource="bin\Connections.config" />

I had to remove BOTH AND put back.

<connectionStrings>
    <add name="UIBuilderContext" connectionString="metadata=res:/ ..... " />
  </connectionStrings>

Removing just still caused the same error.

score 0 · Answer 27 · answered Aug 02 '23 at 12:40

In My Case:-

Issue: Below mentioned error I got when I was trying to scaffolding the code in my asp.net MVC 4.7.2 web application

There was an error running the selected code generator: ‘Exception has been thrown by the target of an invocation.’

Solution: In web-config file, Need to move "configSections" at First-place in "configuration" section. Means the below mentioned sequence need to follow:

<configuration>
  <configSections>
   </configSections>
  <connectionStrings>
  </connectionStrings>
</configuration>

Reason for Error:- When we add new ADO.Net model class, at that time it automatically add the connectionString and the configSections inside the web.config file. But it mis-place the sequence, so we just need the manage sequence as mentioned above.

This solution will automatically said by framework when we run the application, so suggest that after add the entity framework ADO.Net model, one need to run the appplication first. So at that time the framework itself gives the error that "configSections" should be the first-code block inside the "configuration".

Leskyam · Answer 28 · 2016-09-03T22:20:22.030

Using: VS 2015 Community Edition and EF 6.1.3 Implemented also: Seed method, with a personalized class, and configured in the web.config file to run every time that the model changes. This seems to be related to some misconfiguration in the web.config file, in my case, like some of the cases I see in this post with other sections of the file, the section was repeated with different content, but it's repeated the main tag of course. The case of the section out of place, over the section, is also cause of the same behavior and narrow message while try to scaffold.

Matt Gregory · Answer 29 · 2017-10-31T18:11:29.207

Your context class might be throwing an exception.

I was following along in the book "C# 6.0 and the .NET 4.6 Framework" and one of the last exercises of the data access layer section was to add logging. Well, I guess that blows up the scaffold wizard. Probably file permissions on sqllog.txt or HttpRuntime is not defined...who knows. When I commented all this stuff out, it worked again.

namespace AutoLotDAL.EF
{
    using System.Data.Entity;
    using System.Data.Entity.Infrastructure;
    using System.Data.Entity.Infrastructure.Interception;
    using AutoLotDAL.Interception;
    using AutoLotDAL.Models;
    using System;
    using System.Data.Entity.Core.Objects;
    using System.Web;

    public class AutoLotEntities : DbContext
    {
        //static readonly DatabaseLogger databaseLogger =
        //    new DatabaseLogger($"{HttpRuntime.AppDomainAppPath}/sqllog.txt", true);

        public AutoLotEntities()
            : base("name=AutoLotConnection")
        {
            ////DbInterception.Add(new ConsoleWriterInterceptor());
            //databaseLogger.StartLogging();
            //DbInterception.Add(databaseLogger);

            //// Interceptor code
            //var context = (this as IObjectContextAdapter).ObjectContext;
            //context.ObjectMaterialized += OnObjectMaterialized;
            //context.SavingChanges += OnSavingChanges;
        }

        //void OnObjectMaterialized(object sender,
        //    System.Data.Entity.Core.Objects.ObjectMaterializedEventArgs e)
        //{

        //}

        //void OnSavingChanges(object sender, EventArgs eventArgs)
        //{
        //    // Sender is of type ObjectContext.  Can get current and original values,
        //    // and cancel/modify the save operation as desired.
        //    var context = sender as ObjectContext;
        //    if (context == null)
        //        return;
        //    foreach (ObjectStateEntry item in
        //        context.ObjectStateManager.GetObjectStateEntries(
        //            EntityState.Modified | EntityState.Added))
        //    {
        //        // Do something important here
        //        if ((item.Entity as Inventory) != null)
        //        {
        //            var entity = (Inventory)item.Entity;
        //            if (entity.Color == "Red")
        //            {
        //                item.RejectPropertyChanges(nameof(entity.Color));
        //            }
        //        }
        //    }
        //}

        //protected override void Dispose(bool disposing)
        //{
        //    DbInterception.Remove(databaseLogger);
        //    databaseLogger.StopLogging();
        //    base.Dispose(disposing);
        //}

        public virtual DbSet<CreditRisk> CreditRisks { get; set; }
        public virtual DbSet<Customer> Customers { get; set; }
        public virtual DbSet<Inventory> Inventory { get; set; }
        public virtual DbSet<Order> Orders { get; set; }
    }
}

score -7 · Answer 30 · answered May 20 '14 at 11:33

-7

EF 6.1 does not Support scaffolding template use EF 5 Chares

answered May 20 '14 at 11:33

Wraza

1

Application can't scaffold items

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