Efcore: Could not load file or assembly 'eShop, Culture=neutral, PublicKeyToken=null'

[tonygeorgiew]

I made 2 separate projects today and both of them have this issue.
~1st Project
solution name: eShop with assemblies/classlibraries eShop.Data/eShop.Data.Models/eShop.Web/eShop.Common/eShop.Infrastructure

AppDbContext/DesigntimeDb.../etc is in eShop.Data
My web startup has
```C#
services.AddDbContext(options =>
{
options.UseSqlServer(this.configuration["ConnectionStrings:DefaultConnection"], b => b.MigrationsAssembly("eShop.Data"));
options.UseOpenIddict();
});

I have selected eShop.Data in my PMC console and the following goes : 

PM> add-migration 'initial model'
Microsoft.AspNetCore.DataProtection.KeyManagement.XmlKeyManager[0]
User profile is available. Using 'C:\Users\admin\AppData\Local\ASP.NET\DataProtection-Keys' as key repository and Windows DPAPI to encrypt keys at rest.
System.IO.FileNotFoundException: Could not load file or assembly 'eShop, Culture=neutral, PublicKeyToken=null'. The system cannot find the file specified.
File name: 'eShop, Culture=neutral, PublicKeyToken=null'
at System.Reflection.RuntimeAssembly._nLoad(AssemblyName fileName, String codeBase, Evidence assemblySecurity, RuntimeAssembly locationHint, StackCrawlMark& stackMark, IntPtr pPrivHostBinder, Boolean throwOnFileNotFound, Boolean forIntrospection, Boolean suppressSecurityChecks, IntPtr ptrLoadContextBinder)
at System.Reflection.RuntimeAssembly.InternalLoadAssemblyName(AssemblyName assemblyRef, Evidence assemblySecurity, RuntimeAssembly reqAssembly, StackCrawlMark& stackMark, IntPtr pPrivHostBinder, Boolean throwOnFileNotFound, Boolean forIntrospection, IntPtr ptrLoadContextBinder)
at System.Reflection.Assembly.Load(AssemblyName assemblyRef)
at Microsoft.EntityFrameworkCore.Migrations.Internal.MigrationsAssembly..ctor(ICurrentDbContext currentContext, IDbContextOptions options, IMigrationsIdGenerator idGenerator)
--- End of stack trace from previous location where exception was thrown ---
at System.Runtime.ExceptionServices.ExceptionDispatchInfo.Throw()
at Microsoft.Extensions.DependencyInjection.ServiceLookup.CallSiteRuntimeResolver.VisitConstructor(ConstructorCallSite constructorCallSite, ServiceProvider provider)
at Microsoft.Extensions.DependencyInjection.ServiceLookup.CallSiteVisitor2.VisitCallSite(IServiceCallSite callSite, TArgument argument) at Microsoft.Extensions.DependencyInjection.ServiceLookup.CallSiteRuntimeResolver.VisitScoped(ScopedCallSite scopedCallSite, ServiceProvider provider) at Microsoft.Extensions.DependencyInjection.ServiceLookup.CallSiteVisitor2.VisitCallSite(IServiceCallSite callSite, TArgument argument)
at Microsoft.Extensions.DependencyInjection.ServiceLookup.CallSiteRuntimeResolver.VisitConstructor(ConstructorCallSite constructorCallSite, ServiceProvider provider)
at Microsoft.Extensions.DependencyInjection.ServiceLookup.CallSiteVisitor2.VisitCallSite(IServiceCallSite callSite, TArgument argument) at Microsoft.Extensions.DependencyInjection.ServiceLookup.CallSiteRuntimeResolver.VisitScoped(ScopedCallSite scopedCallSite, ServiceProvider provider) at Microsoft.Extensions.DependencyInjection.ServiceLookup.CallSiteVisitor2.VisitCallSite(IServiceCallSite callSite, TArgument argument)
at Microsoft.Extensions.DependencyInjection.ServiceProvider.<>c__DisplayClass22_0.b__0(ServiceProvider provider)
at Microsoft.Extensions.DependencyInjection.ServiceProvider.GetService(Type serviceType)
at Microsoft.Extensions.DependencyInjection.ServiceProviderServiceExtensions.GetServiceT
at Microsoft.EntityFrameworkCore.Design.Internal.DesignTimeServicesBuilder.<>c__DisplayClass6_0.b__7(IServiceProvider _)
at Microsoft.Extensions.DependencyInjection.ServiceLookup.CallSiteRuntimeResolver.VisitFactory(FactoryCallSite factoryCallSite, ServiceProvider provider)
at Microsoft.Extensions.DependencyInjection.ServiceLookup.CallSiteVisitor2.VisitCallSite(IServiceCallSite callSite, TArgument argument) at Microsoft.Extensions.DependencyInjection.ServiceLookup.CallSiteRuntimeResolver.VisitTransient(TransientCallSite transientCallSite, ServiceProvider provider) at Microsoft.Extensions.DependencyInjection.ServiceLookup.CallSiteVisitor2.VisitCallSite(IServiceCallSite callSite, TArgument argument)
at Microsoft.Extensions.DependencyInjection.ServiceProvider.<>c__DisplayClass22_0.b__0(ServiceProvider provider)
at Microsoft.Extensions.DependencyInjection.ServiceProvider.GetService(Type serviceType)
at Microsoft.Extensions.DependencyInjection.ServiceProviderServiceExtensions.GetServiceT
at Microsoft.EntityFrameworkCore.Design.Internal.MigrationsOperations.EnsureServices(IServiceProvider services)
at Microsoft.EntityFrameworkCore.Design.Internal.MigrationsOperations.AddMigration(String name, String outputDir, String contextType)
at Microsoft.EntityFrameworkCore.Design.OperationExecutor.AddMigrationImpl(String name, String outputDir, String contextType)
at Microsoft.EntityFrameworkCore.Design.OperationExecutor.AddMigration.<>c__DisplayClass0_1.<.ctor>b__0()
at Microsoft.EntityFrameworkCore.Design.OperationExecutor.OperationBase.<>c__DisplayClass3_0`1.b__0()
at Microsoft.EntityFrameworkCore.Design.OperationExecutor.OperationBase.Execute(Action action)

Could not load file or assembly 'eShop, Culture=neutral, PublicKeyToken=null'. The system cannot find the file specified.
```

eShop.Data.csproj
https://github.com/tonygeorgiew/eShop/blob/master/Data/eShop.Data/eShop.Data.csproj

eShop.Web.csproj
https://github.com/tonygeorgiew/eShop/blob/master/Web/eShop.Web/eShop.Web.csproj

Database Provider: Microsoft.EntityFrameworkCore.SqlServer
Operating system: Windows 7 Ultimate 64 bit
IDE: Visual Studio 2017 15.5

Note: The second project I made all the names of classes and files were the same except the solution name which was eShop-SPA, upon entering add-migration the same error appeared 'eShop, Culture=neutral, PublicKeyToken=null'.

[bricelam]

Could you add the output with --verbose?

[tonygeorgiew]

add-migartion 'initial' --verbose
The term 'add-migartion' is not recognized as the name of a cmdlet, function, script file, or operable program. Check the spelling of the name, or if a path was included, verify th
at the path is correct and try again.At line:1 char:1

• add-migartion 'initial' --verbose
• ~~~~~
  
  
  
  • CategoryInfo : ObjectNotFound: (add-migartion:String) [], CommandNotFoundException
  
  
  • FullyQualifiedErrorId : CommandNotFoundException
  
  

Same packages same project 1 week later, will downgrade VS to 2015 or 15.4 and see if the issue gets fixed

[ErikEJ]

You are spelling it wrong 😁

[tonygeorgiew]

@ErikEJ You are right, sorry for the stupid mistake.
Getting the same error now with -verbose

============================
PM> add-migration 'initial model' -verbose
Using project 'Data\eShop.Data'.
Using startup project 'Web\eShop.Web'.
Build started...
Build succeeded.
C:\Program Files\dotnet\dotnet.exe exec --depsfile C:\Users\admin\source\repos\eShop\Web\eShop.Web\bin\Debug\netcoreapp2.0\eShop.Web.deps.json --additionalprobingpath C:\Users\admin.nuget\packages --additionalprobingpath "C:\Program Files (x86)\Microsoft SDKs\NuGetPackagesFallback" --additionalprobingpath "C:\Program Files\dotnet\sdk\NuGetFallbackFolder" --runtimeconfig C:\Users\admin\source\repos\eShop\Web\eShop.Web\bin\Debug\netcoreapp2.0\eShop.Web.runtimeconfig.json "C:\Program Files\dotnet\sdk\NuGetFallbackFolder\microsoft.entityframeworkcore.tools\2.0.1\tools\netcoreapp2.0\ef.dll" migrations add "initial model" --json --verbose --no-color --prefix-output --assembly C:\Users\admin\source\repos\eShop\Web\eShop.Web\bin\Debug\netcoreapp2.0\eShop.Data.dll --startup-assembly C:\Users\admin\source\repos\eShop\Web\eShop.Web\bin\Debug\netcoreapp2.0\eShop.Web.dll --project-dir C:\Users\admin\source\repos\eShop\Data\eShop.Data\ --root-namespace eShop.Data
Using assembly 'eShop.Data'.
Using startup assembly 'eShop.Web'.
Using application base 'C:\Users\admin\source\repos\eShop\Web\eShop.Web\bin\Debug\netcoreapp2.0'.
Using working directory 'C:\Users\admin\source\repos\eShop\Web\eShop.Web'.
Using root namespace 'eShop.Data'.
Using project directory 'C:\Users\admin\source\repos\eShop\Data\eShop.Data\'.
Finding DbContext classes...
Finding IDesignTimeDbContextFactory implementations...
Finding application service provider...
Finding BuildWebHost method...
Using environment 'Development'.
Using application service provider from BuildWebHost method on 'Program'.
Microsoft.AspNetCore.DataProtection.KeyManagement.XmlKeyManager[0]
User profile is available. Using 'C:\Users\admin\AppData\Local\ASP.NET\DataProtection-Keys' as key repository and Windows DPAPI to encrypt keys at rest.
Found DbContext 'ApplicationDbContext'.
Finding DbContext classes in the project...
Using DbContext factory 'DesignTimeDbContextFactory'.
Using context 'ApplicationDbContext'.
Finding design-time services for provider 'Microsoft.EntityFrameworkCore.SqlServer'...
Using design-time services from provider 'Microsoft.EntityFrameworkCore.SqlServer'.
Finding IDesignTimeServices implementations in assembly 'eShop.Web'...
No design-time services were found.
System.IO.FileNotFoundException: Could not load file or assembly 'eShop, Culture=neutral, PublicKeyToken=null'. The system cannot find the file specified.
File name: 'eShop, Culture=neutral, PublicKeyToken=null'
at System.Reflection.RuntimeAssembly._nLoad(AssemblyName fileName, String codeBase, Evidence assemblySecurity, RuntimeAssembly locationHint, StackCrawlMark& stackMark, IntPtr pPrivHostBinder, Boolean throwOnFileNotFound, Boolean forIntrospection, Boolean suppressSecurityChecks, IntPtr ptrLoadContextBinder)
at System.Reflection.RuntimeAssembly.InternalLoadAssemblyName(AssemblyName assemblyRef, Evidence assemblySecurity, RuntimeAssembly reqAssembly, StackCrawlMark& stackMark, IntPtr pPrivHostBinder, Boolean throwOnFileNotFound, Boolean forIntrospection, IntPtr ptrLoadContextBinder)
at System.Reflection.Assembly.Load(AssemblyName assemblyRef)
at Microsoft.EntityFrameworkCore.Migrations.Internal.MigrationsAssembly..ctor(ICurrentDbContext currentContext, IDbContextOptions options, IMigrationsIdGenerator idGenerator)
--- End of stack trace from previous location where exception was thrown ---
at System.Runtime.ExceptionServices.ExceptionDispatchInfo.Throw()
at Microsoft.Extensions.DependencyInjection.ServiceLookup.CallSiteRuntimeResolver.VisitConstructor(ConstructorCallSite constructorCallSite, ServiceProvider provider)
at Microsoft.Extensions.DependencyInjection.ServiceLookup.CallSiteVisitor2.VisitCallSite(IServiceCallSite callSite, TArgument argument) at Microsoft.Extensions.DependencyInjection.ServiceLookup.CallSiteRuntimeResolver.VisitScoped(ScopedCallSite scopedCallSite, ServiceProvider provider) at Microsoft.Extensions.DependencyInjection.ServiceLookup.CallSiteVisitor2.VisitCallSite(IServiceCallSite callSite, TArgument argument)
at Microsoft.Extensions.DependencyInjection.ServiceLookup.CallSiteRuntimeResolver.VisitConstructor(ConstructorCallSite constructorCallSite, ServiceProvider provider)
at Microsoft.Extensions.DependencyInjection.ServiceLookup.CallSiteVisitor2.VisitCallSite(IServiceCallSite callSite, TArgument argument) at Microsoft.Extensions.DependencyInjection.ServiceLookup.CallSiteRuntimeResolver.VisitScoped(ScopedCallSite scopedCallSite, ServiceProvider provider) at Microsoft.Extensions.DependencyInjection.ServiceLookup.CallSiteVisitor2.VisitCallSite(IServiceCallSite callSite, TArgument argument)
at Microsoft.Extensions.DependencyInjection.ServiceProvider.<>c__DisplayClass22_0.b__0(ServiceProvider provider)
at Microsoft.Extensions.DependencyInjection.ServiceProvider.GetService(Type serviceType)
at Microsoft.Extensions.DependencyInjection.ServiceProviderServiceExtensions.GetServiceT
at Microsoft.EntityFrameworkCore.Design.Internal.DesignTimeServicesBuilder.<>c__DisplayClass6_0.b__7(IServiceProvider _)
at Microsoft.Extensions.DependencyInjection.ServiceLookup.CallSiteRuntimeResolver.VisitFactory(FactoryCallSite factoryCallSite, ServiceProvider provider)
at Microsoft.Extensions.DependencyInjection.ServiceLookup.CallSiteVisitor2.VisitCallSite(IServiceCallSite callSite, TArgument argument) at Microsoft.Extensions.DependencyInjection.ServiceLookup.CallSiteRuntimeResolver.VisitTransient(TransientCallSite transientCallSite, ServiceProvider provider) at Microsoft.Extensions.DependencyInjection.ServiceLookup.CallSiteVisitor2.VisitCallSite(IServiceCallSite callSite, TArgument argument)
at Microsoft.Extensions.DependencyInjection.ServiceProvider.<>c__DisplayClass22_0.b__0(ServiceProvider provider)
at Microsoft.Extensions.DependencyInjection.ServiceProvider.GetService(Type serviceType)
at Microsoft.Extensions.DependencyInjection.ServiceProviderServiceExtensions.GetServiceT
at Microsoft.EntityFrameworkCore.Design.Internal.MigrationsOperations.EnsureServices(IServiceProvider services)
at Microsoft.EntityFrameworkCore.Design.Internal.MigrationsOperations.AddMigration(String name, String outputDir, String contextType)
at Microsoft.EntityFrameworkCore.Design.OperationExecutor.AddMigrationImpl(String name, String outputDir, String contextType)
at Microsoft.EntityFrameworkCore.Design.OperationExecutor.AddMigration.<>c__DisplayClass0_1.<.ctor>b__0()
at Microsoft.EntityFrameworkCore.Design.OperationExecutor.OperationBase.<>c__DisplayClass3_0`1.b__0()
at Microsoft.EntityFrameworkCore.Design.OperationExecutor.OperationBase.Execute(Action action)

Could not load file or assembly 'eShop, Culture=neutral, PublicKeyToken=null'. The system cannot find the file specified.

[bricelam]

...and you're positive the MigrationsAssembly() call is correct and doesn't use this non-existent "eShop" assembly name?

[tonygeorgiew]

Yes, I believe highly so,
you can see the source code here yourself https://github.com/tonygeorgiew/eShop

[bricelam]

It's trying to use the eShop assembly specified here.

See EF Core Design-time DbContext Creation for more information about IDesignTimeDbContextFactory and when it gets used.