Your startup project 'project' doesn't reference Microsoft.EntityFrameworkCore.Design

Question

I'm building WPF application with the EntityFrameworkCore version 2.2.2

However, when i want to Add-Migration it output me an error...

Your startup project 'project' doesn't reference Microsoft.EntityFrameworkCore.Design. This package is required for the Entity Framework Core Tools to work. Ensure your startup project is correct, install the package, and try again.

I don't know why this is happen, because I can use it before this error come up.

This is my packages.config file

<?xml version="1.0" encoding="utf-8"?>
<packages>
  <package id="Costura.Fody" version="3.3.2" targetFramework="net461" />
  <package id="Fody" version="4.0.2" targetFramework="net461" developmentDependency="true" />
  <package id="Microsoft.CSharp" version="4.5.0" targetFramework="net461" />
  <package id="Microsoft.Data.Sqlite.Core" version="2.2.2" targetFramework="net461" />
  <package id="Microsoft.DotNet.PlatformAbstractions" version="2.1.0" targetFramework="net461" />
  <package id="Microsoft.EntityFrameworkCore" version="2.2.2" targetFramework="net461" />
  <package id="Microsoft.EntityFrameworkCore.Abstractions" version="2.2.2" targetFramework="net461" />
  <package id="Microsoft.EntityFrameworkCore.Analyzers" version="2.2.2" targetFramework="net461" />
  <package id="Microsoft.EntityFrameworkCore.Design" version="2.2.2" targetFramework="net461" />
  <package id="Microsoft.EntityFrameworkCore.Relational" version="2.2.2" targetFramework="net461" />
  <package id="Microsoft.EntityFrameworkCore.Sqlite" version="2.2.2" targetFramework="net461" />
  <package id="Microsoft.EntityFrameworkCore.Sqlite.Core" version="2.2.2" targetFramework="net461" />
  <package id="Microsoft.EntityFrameworkCore.Tools" version="2.2.2" targetFramework="net461" developmentDependency="true" />
  <package id="Microsoft.Extensions.Caching.Abstractions" version="2.2.0" targetFramework="net461" />
  <package id="Microsoft.Extensions.Caching.Memory" version="2.2.0" targetFramework="net461" />
  <package id="Microsoft.Extensions.Configuration" version="2.2.0" targetFramework="net461" />
  <package id="Microsoft.Extensions.Configuration.Abstractions" version="2.2.0" targetFramework="net461" />
  <package id="Microsoft.Extensions.Configuration.Binder" version="2.2.0" targetFramework="net461" />
  <package id="Microsoft.Extensions.DependencyInjection" version="2.2.0" targetFramework="net461" />
  <package id="Microsoft.Extensions.DependencyInjection.Abstractions" version="2.2.0" targetFramework="net461" />
  <package id="Microsoft.Extensions.DependencyModel" version="2.1.0" targetFramework="net461" />
  <package id="Microsoft.Extensions.Logging" version="2.2.0" targetFramework="net461" />
  <package id="Microsoft.Extensions.Logging.Abstractions" version="2.2.0" targetFramework="net461" />
  <package id="Microsoft.Extensions.Options" version="2.2.0" targetFramework="net461" />
  <package id="Microsoft.Extensions.Primitives" version="2.2.0" targetFramework="net461" />
  <package id="Newtonsoft.Json" version="9.0.1" targetFramework="net461" />
  <package id="Remotion.Linq" version="2.2.0" targetFramework="net461" />
  <package id="SQLitePCLRaw.bundle_green" version="1.1.12" targetFramework="net461" />
  <package id="SQLitePCLRaw.core" version="1.1.12" targetFramework="net461" />
  <package id="SQLitePCLRaw.lib.e_sqlite3.linux" version="1.1.12" targetFramework="net461" />
  <package id="SQLitePCLRaw.lib.e_sqlite3.osx" version="1.1.12" targetFramework="net461" />
  <package id="SQLitePCLRaw.lib.e_sqlite3.v110_xp" version="1.1.12" targetFramework="net461" />
  <package id="SQLitePCLRaw.provider.e_sqlite3.net45" version="1.1.12" targetFramework="net461" />
  <package id="System.Buffers" version="4.4.0" targetFramework="net461" />
  <package id="System.Collections.Immutable" version="1.5.0" targetFramework="net461" />
  <package id="System.ComponentModel.Annotations" version="4.5.0" targetFramework="net461" />
  <package id="System.Diagnostics.DiagnosticSource" version="4.5.0" targetFramework="net461" />
  <package id="System.Interactive.Async" version="3.2.0" targetFramework="net461" />
  <package id="System.Memory" version="4.5.1" targetFramework="net461" />
  <package id="System.Numerics.Vectors" version="4.4.0" targetFramework="net461" />
  <package id="System.Runtime.CompilerServices.Unsafe" version="4.5.1" targetFramework="net461" />
  <package id="System.Runtime.InteropServices.RuntimeInformation" version="4.0.0" targetFramework="net461" />
</packages>

The package is already installed.

Thanks a lot for any helps.

Answer 1

Your startup project 'Lmss.Web' doesn't reference Microsoft.EntityFrameworkCore.Design. This package is required for the Entity Framework Core Tools to work. Ensure your startup project is correct, install the package, and try again.

During the migration, this error shows you need to install Microsoft.EntityFrameworkCore.Design in your startup project. This will help you to run the migration.

Install this:

Answer 2

I faced the same Problem. You have to change startup project. Whichever project you want to migrate, make it a startup project. Then set as package manager console default project. Finally, you can add migration. Like : add-migration initial

Answer 3

Install it again using PMC and then it will find the reference:

PM> dotnet add package Microsoft.EntityFrameworkCore.Design

Answer 4

I did install it using this command and it works !

I'm using .net core version 3.1.1

dotnet add package Microsoft.EntityFrameworkCore.Design --version 3.1.1

Answer 5

Add-Migration may be getting confused since you are using Costura to embed assemblies. Try removing costura to see if that resolves the issue.