ASP.NET Core Scaffolding does not work in VS 2017

Question

I have a beginner ASP.NET Core project in Visual Studio 2017, and I am at the scaffolding step of the HelloWorld. The Scaffolding does not work, I tested on a first computer, then at a second one...

when I try to generate a controller with views , it gives the following error on the first machine:

Microsoft Visual Studio

Error

There was an error running the selected code generator:

'Unhandled Exception: System.IO.FileNotFoundException: Could not load file or assembly 'Microsoft.VisualStudio.Web.CodeGeneration.Utils, Version=1.1.1.0, Culture=neutral, PublicKeyToken=adb9793829ddae60'. The system cannot find the file specified. at Microsoft.VisualStudio.Web.CodeGeneration.Design.Program.Main(String[] args)'

OK

On the second machine:

Microsoft Visual Studio

Error

There was an error running the selected code generator:

'Error: assembly specified in the dependencies manifest was not found -- package: 'microsoft.applicationinsights.aspnetcore', version: '2.1.0', path: 'lib/netstandard1.6/Microsoft.ApplicationInsights.AspNetCore.dll''

OK

I had an error in my code. When fixed it ran smoothly. (one of my classes was private with an active method) — E. G., Mar 23 '20 at 02:44
Just don't forget to install Microsoft.VisualStudio.Web.CodeGeneration.Utils. Especially if you are new to this kind of stuff like me. That's what fixed it for me. — André Yuhai, May 14 '20 at 22:37

score 24 · Accepted Answer · edited Dec 10 '18 at 16:09

24

The following works for me.

I deleted bin & obj folders, build the project again and it works.

In case if it gives you error: it couldn't find project.deps.json in debug folder.

Set project to debug, ran it and now you can add scaffolded items.

edited Dec 10 '18 at 16:09

serge

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answered Apr 05 '18 at 12:42

Sohail Riaz

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AngelDown · Answer 2 · 2017-07-30T13:14:11.840

10

Clear local NuGet cache with the command from console:

dotnet nuget locals all --clear

Restore all Packages

Install (or update) NuGet package Microsoft.CodeAnalysis.CSharp.Workspaces version 2.0.0 (or higher) EDIT: It seams versions 2.3.0 and 2.3.1 cause some problems. So stick with 2.2.0 at most until MS solves this issues (https://github.com/dotnet/roslyn/issues/20873).

Restore all Packages again and try scaffolding.

That worked for me.

Be sure you have properly referenced these packages in your project:

<PackageReference Include="Microsoft.VisualStudio.Web.CodeGeneration.Design" Version="1.1.1" />

<DotNetCliToolReference Include="Microsoft.VisualStudio.Web.CodeGeneration.Tools" Version="1.0.1" />

My projects uses Asp.Net Core 1.1.2 and VS2017 Community

edited Jul 30 '17 at 13:14

answered Jul 30 '17 at 12:08

AngelDown

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What I did is repairing the VS-2017 installation (Enterprise Edition)... And now the scaffolding works. – serge Jul 31 '17 at 09:41
I've tryed reparing, it didn't change a thing. – Jean-Charbel VANNIER Jul 31 '17 at 12:38
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Preview bits for `Microsoft.VisualStudio.Web.CodeGeneration.Design` were apparently installed with VS 2019 Preview 3. Downgrading this package to `2.2.3` resolved the issue for me. – CalvinDale May 25 '19 at 14:25
@CalvinDale thank you. downgrading Microsoft.VisualStudio.Web.CodeGeneration.Design package resolved the issue for me too. – mina morsali Sep 29 '19 at 20:01
@CalvinDale Please post this as an answer since it seemed to work out for multiple people including me, thanks – Wouter Vanherck Oct 23 '19 at 09:03
Thanks for `dotnet nuget locals all --clear` < – Peyman Majidi May 09 '21 at 08:12

score 6 · Answer 3 · answered Dec 08 '18 at 09:44

I has the same situation. On .net core version 2.2 and with VS 2017 Enterprise.

The next instruction hepls for me:

open VS with Admin rights.
load solution to VS
add controller from scaffolding menu. VS will install 'Microsoft.VisualStudio.Web.CodeGeneration.Design' and 'Microsoft.VisualStudio.Web.CodeGeneration.Tools' packages.
close VS
open VS and load project. Add controllers via scaffloading is working fine

Maybe this instruction helps somebody, Thanks.

score 5 · Answer 4 · answered Feb 19 '20 at 10:37

For the benefit of searchers:

I got this in VS2019. The cause was that my code was broken.

Didn't realise why to start, but when you realise that code generation is a nuget package; if the project doesn't build, then Visual Studio can't get to that package.

Once I got the code compiling, this error went away.

score 2 · Answer 5 · answered Oct 30 '19 at 05:28

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you should change the version of Microsoft.VisualStudio.Web.CodeGeneration.Design exactly like the version of Microsoft.AspNetCore.App

answered Oct 30 '19 at 05:28

Mohammad Rajabi

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where to do that? – André Yuhai May 14 '20 at 22:32

score 1 · Answer 6 · answered Nov 17 '19 at 14:31

I was trying to run the command bellow with the version 3.0.0 of asp.net core installed, so I got the same error Command: dotnet aspnet-codegenerator controller -name MoviesController -m Movie -dc MvcMovieContext --relativeFolderPath Controllers --useDefaultLayout --referenceScriptLibraries

Error: Scaffolding failed. Could not load file or assembly 'Microsoft.VisualStudio.Web.CodeGeneration, Version=3.0.0.0, Culture=neutral, PublicKeyToken=adb9793829ddae60'. The system cannot find the file specified.

Solution:

dotnet nuget locals all --clear

dotnet remove package Microsoft.VisualStudio.Web.CodeGeneration.Utils

Change the PackageRefere for the version 2.2.0

Run the command again. dotnet aspnet-codegenerator controller -name MoviesController -m Movie -dc MvcMovieContext --relativeFolderPath Controllers --useDefaultLayout --referenceScriptLibraries

score 1 · Answer 7 · answered Dec 27 '20 at 09:46

I fixed this by uninstalling all entity framework packages using nuget package manager and again reinstall with same version.

Microsoft.EntityFrameworkCore
Microsoft.EntityFrameworkCore.Design
Microsoft.EntityFrameworkCore.SqlServer

(3.10 version)

score 0 · Answer 8 · answered Oct 28 '20 at 13:16

Solution:

Go to VS2019 --> Dependencies -->Packages
Click on Manage NuGet
In the search type "Microsoft.VisualStudio.Web.CodeGeneration.Utils" or the Dll that is missing.
Click Install.
Rebuild the solution
Then add the Scaffolding item. It works..:-)

score 0 · Answer 9 · answered Mar 07 '21 at 05:57

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go to solution explorer -> clean solution then build solution

this worked for me.

answered Mar 07 '21 at 05:57

Akshay Bhanderi

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score 0 · Answer 10 · answered Apr 23 '21 at 10:36

I was receiving different error messages. Actually there was nothing specific, no mention of dependencies or assemblies. I tried all of the above suggestions with no success. Then I tried letting it create a new DbContext instead of specifying an existing one. That resolved my issue.

score 0 · Answer 11 · answered May 08 '21 at 17:45

0

On menu --> Compile --> Clean Solution
On menu --> Compile --> Build Solution.

Then repeat de creation of crud using scaffolding. That works for me. Thanks

answered May 08 '21 at 17:45

Diego Santamaria

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ASP.NET Core Scaffolding does not work in VS 2017

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