Version mismatches in 2.1 and 2.2 patch updates (often causes FileLoadException)

[natemcmaster]

Some ASP.NET Core 2.1 users have been affected by a bug in the .NET Core host (see https://github.com/dotnet/core-setup/issues/4512) which can cause apps to fail with System.IO.FileLoadException. The issue may also be present in your app, even if the app does not fail with System.IO.FileLoadException.

Affected versions

.NET Core, 2.1.1 through 2.1.4 (all OSes), 2.1.7 (Windows only), 2.2.1 (Windows only)

Symptom 1

ASP.NET Core apps running on the Microsoft.AspNetCore.App shared framework may fail to run after the machine-wide version of .NET Core is updated. Apps fail with an error such as:

Unhandled Exception: System.IO.FileLoadException: Could not load file or assembly 'Microsoft.Extensions.Identity.Core, Version=2.1.3.0, Culture=neutral, PublicKeyToken=adb9793829ddae60'. The located assembly's manifest definition does not match the assembly reference. (Exception from HRESULT: 0x80131040)
at Diary.Api.Startup.ConfigureServices(IServiceCollection services)

Symptom 2

When publishing an ASP.NET Core application which references Microsoft.AspNetCore.App, additional Microsoft assemblies are in the publish output.

For example, if you run dotnet publish --output PublishDir/ and you see Microsoft.Extensions.*.dll or Microsoft.AspNetCore.*.dll files in PublishDir/, you may be running into this issue.

Cause

This issue is typically caused by .csproj files which have a PackageReference to a package which is already part of Microsoft.AspNetCore.App.

For example,

<ItemGroup>
  <PackageReference Include="Microsoft.AspNetCore.App" />
  <PackageReference Include="Microsoft.AspNetCore.SignalR" Version="1.0.3" />
</ItemGroup>

The Microsoft.AspNetCore.SignalR package is already pulled in as a part of Microsoft.AspNetCore.App, so does not normally need to be referenced. The presence of this reference causes a mismatch of versions, which in turn causes a problem with the .NET Core host, as described in https://github.com/dotnet/core-setup/issues/4376.

More technical details here: Azure/app-service-announcements-discussions#65 (comment)

Workaround 1

Remove PackageReference's which are already part of Microsoft.AspNetCore.App. You can find a list of what this package pulls in by looking at https://www.nuget.org/packages/microsoft.aspnetcore.app#show-dependency-groups. This will avoid the version mismatch.

Workaround 2

Upgrade the Microsoft.AspNetCore.App PackageReference to the latest 2.1.x version by adding the Version attribute.

  <PackageReference Include="Microsoft.AspNetCore.App" Version="2.1.3" />

⚠️ This may have unintended consequences on your deployment environment. If the deployment environment does not have the the 2.1.3 runtime, apps will fail to start with an error. In Azure or apps hosted behind IIS, this may appear as HTTP 502.5 error.

[mirekholec]

I found issue similar to symptom 2, but with some differences:

I have ASP.NET Core application (Microsoft.AspNetCore.App 2.1.2) FDD deployed to Azure App Service (West Europe). Everything worked fine for three weeks but 19/09/2018 all of the sudden it starts to fail. I tryied dotnet tool on App Service (Kudu) and there is only App/All runtime version 2.1.1 and 2.1.4 on the machine.

My csproj file contains:

    <PackageReference Include="Microsoft.AspNetCore.App" Version="2.1.2" />
    <PackageReference Include="Microsoft.EntityFrameworkCore.Sqlite" Version="2.1.2" />
    <PackageReference Include="Microsoft.ApplicationInsights.AspNetCore" Version="2.4.1" /> 

and it is failing on this error:

Application: dotnet.exe CoreCLR Version: 4.6.26814.3 Description: The process was terminated due to an unhandled exception. Exception Info: System.IO.FileLoadException: Could not load file or assembly 'Microsoft.EntityFrameworkCore, Version=2.1.3.0, Culture=neutral, PublicKeyToken=adb9793829ddae60'. The located assembly's manifest definition does not match the assembly reference. (Exception from HRESULT: 0x80131040) at DotnetTalks.Startup.<>c__DisplayClass7_0.<ConfigureServices>b__3(DbContextOptionsBuilder opt) at Microsoft.Extensions.DependencyInjection.EntityFrameworkServiceCollectionExtensions.<>c__DisplayClass1_0`2.<AddDbContext>b__0(IServiceProvider p, DbContextOptionsBuilder b) at Microsoft.Extensions.DependencyInjection.EntityFrameworkServiceCollectionExtensions.DbContextOptionsFactory[TContext](IServiceProvider applicationServiceProvider, Action`2 optionsAction) at Microsoft.Extensions.DependencyInjection.EntityFrameworkServiceCollectionExtensions.<>c__DisplayClass10_0`1.<AddCoreServices>b__0(IServiceProvider p) at Microsoft.Extensions.DependencyInjection.ServiceLookup.CallSiteRuntimeResolver.VisitFactory(FactoryCallSite factoryCallSite, ServiceProviderEngineScope scope) at Microsoft.Extensions.DependencyInjection.ServiceLookup.CallSiteVisitor`2.VisitCallSite(IServiceCallSite callSite, TArgument argument) at Microsoft.Extensions.DependencyInjection.ServiceLookup.CallSiteRuntimeResolver.VisitScoped(ScopedCallSite scopedCallSite, ServiceProviderEngineScope scope) at Microsoft.Extensions.DependencyInjection.ServiceLookup.CallSiteVisitor`2.VisitCallSite(IServiceCallSite callSite, TArgument argument) at Microsoft.Extensions.DependencyInjection.ServiceLookup.CallSiteRuntimeResolver.VisitConstructor(ConstructorCallSite constructorCallSite, ServiceProviderEngineScope scope) at Microsoft.Extensions.DependencyInjection.ServiceLookup.CallSiteVisitor`2.VisitCallSite(IServiceCallSite callSite, TArgument argument) at Microsoft.Extensions.DependencyInjection.ServiceLookup.CallSiteRuntimeResolver.VisitScoped(ScopedCallSite scopedCallSite, ServiceProviderEngineScope scope) at Microsoft.Extensions.DependencyInjection.ServiceLookup.CallSiteVisitor`2.VisitCallSite(IServiceCallSite callSite, TArgument argument) at Microsoft.Extensions.DependencyInjection.ServiceLookup.DynamicServiceProviderEngine.<>c__DisplayClass1_0.<RealizeService>b__0(ServiceProviderEngineScope scope) at Microsoft.Extensions.DependencyInjection.ServiceLookup.ServiceProviderEngine.GetService(Type serviceType, ServiceProviderEngineScope serviceProviderEngineScope) at Microsoft.Extensions.DependencyInjection.ServiceLookup.ServiceProviderEngineScope.GetService(Type serviceType) at Microsoft.Extensions.DependencyInjection.ServiceProviderServiceExtensions.GetService[T](IServiceProvider provider) at DotnetTalks.Program.Main(String[] args) in D:\a\1\s\DotnetTalks\Program.cs:line 15
</Data>

I tryied to change the file this way:

    <PackageReference Include="Microsoft.AspNetCore.App" />
    <PackageReference Include="Microsoft.EntityFrameworkCore.Sqlite" Version="2.1.2" />
    <PackageReference Include="Microsoft.ApplicationInsights.AspNetCore" Version="2.4.1" /> 

but the error remains. When I explicitly change Sqlite version this way:

<PackageReference Include="Microsoft.EntityFrameworkCore.Sqlite" Version="2.1.2" />

it works. But Microsoft.EntityFrameworkCore.Sqlite is not a part of ASP.NET Core runtime (App).

It is very unpleasant to know that the application can whenever fall down. I found that only safe solution is to deploy application as self-contained. Any ideas how to figure out this issue?

[natemcmaster]

@mholec did you try Workaround 2?

[mirekholec]

I can try it. However the problem is that this kind of error means that my web application my be broken at any time after successful deploy and test.

[natemcmaster]

We have a fix for the issue in 2.1.5 which should be out soon, so only 2.1.1 through 2.1.4 should be affected by this issue. When 2.1.5 is released, I recommend you update your servers.