An assembly specified in the application dependencies manifest (...) was not found

asp.net Core .Net Core asp.net Web-Api2 Upgrade Nuget Package

asp.net Core Problem Overview

I upgraded Microsoft.AspNetCore from 2.0.3 to 2.0.5 and my WebAPI project, although running successfully locally, fails to start in production (IIS). Everything was fine in production until this upgrade. The error message produced in the log directory is as follows:

Error:
  An assembly specified in the application dependencies manifest (MyProject.WebAPI.deps.json) was not found:
    package: 'Microsoft.AspNetCore.Mvc.Abstractions', version: '2.0.2'
    path: 'lib/netstandard2.0/Microsoft.AspNetCore.Mvc.Abstractions.dll'

  This assembly was expected to be in the local runtime store as the application was published using the following target manifest files:
    aspnetcore-store-2.0.5.xml

Could someone explain to me the details of exactly what this means? I assume it's a version mismatch of sorts, but why is this occurring? I thought the latest stable releases of NuGet packages weren't supposed to have such issues.

I was able to resolve the issue by downgrading Microsoft.AspNetCore.All from 2.0.5 to 2.0.3, but would like to find a better solution to the issue so I can use the most up-to-date version of this package.

asp.net Core Solutions

Solution 1 - asp.net Core

Development machines usually have the SDK installed but on production the runtime only.

Add the following to your .csproj file and publish again.

<PropertyGroup>               
    <PublishWithAspNetCoreTargetManifest>false</PublishWithAspNetCoreTargetManifest>
</PropertyGroup>

Solution 2 - asp.net Core

Sometimes this is related to the Startup Project, For example if the migration is a class library in Azure Functions project. You have to make sure when you run Add-Migration while the EF Library project is selected as Startup Project.

Solution 3 - asp.net Core

For me, the marked answer didn't solve the issue. My issue was when trying to Add-Migration

Add-Migration -Name initial-migration -Context Mysln.Data.MyDbContext -StartupProject Mysln -Project Mysln.Core

And the error was like this:

I solved it by downgrading all my Entityframework packages to 2.0.0 instead of the latest 2.2.0-preview one.

Solution 4 - asp.net Core

To solve the first half of the error message, An assembly specified in the application dependencies manifest (…) was not found be sure to always use the publish output when deploying to a target sever.

For a self-contained application it can be found in

bin\Release\netcoreapp2.0\win81-x64\publish

or for framework-dependent deployments in

bin\Release\netcoreapp2.0\publish

The output in the directories above are meant to be used in development only, since they are specific to machine and user configuration built with.

Taken from a related answer.

Solution 5 - asp.net Core

If you have more than one project in your solution like me:

and if you want to scaffold dbcontext in your "non startup" project (InstantOrder.Functions.Data in my case) then you should add the -StartupProject parameter of the Scaffold-DbContext command like this -

Scaffold-DbContext "Server=..." -Project InstantOrder.Functions.Data -StartupProject InstantOrder.Functions.Data

Solution 6 - asp.net Core

2 cents: If you just take from the build folder, the dlls for the dependency aren't provided. If you publish the folder, they are. This was the fix for me.

Solution 7 - asp.net Core

I had this error however my solution was somewhat different from what was posted above. My problem was that I was deploying via a zip file and while building the zip file I wasn't including sub directories therefore required files were not being included.

So if you are publishing via a zip file make sure to include all sub folders while building the zip.

Solution 8 - asp.net Core

I got this error while running Scaffold-DbContext command on the Library project.

Solution:

Remove the Azure Function project from the solution, and then run this command.
After that, use add an existing project feature to add the Azure Function project again in the solution.

Solution 9 - asp.net Core

The correct .NET Core runtime was not installed on my PC. I had NETCore.App 2.1 and 2.2, but the project was targeted to 2.0.

dotnet --list-runtimes

I installed the correct runtime from the dot.net site and it resolved the issue.

Solution 10 - asp.net Core

In most case you get that error because there's misalignment of versions.

I changed the Microsoft.VisualStudio.Web.CodeGeneration.Design version, an it worked.

Before

<PackageReference Include="Microsoft.VisualStudio.Web.CodeGeneration.Design" Version="3.1.0" />

After

<PackageReference Include="Microsoft.VisualStudio.Web.CodeGeneration.Design" Version="2.2.4" />

Solution 11 - asp.net Core

This happened to me when I published my Lambda to AWS after renaming the project. I deleted both the obj and bin folders, rebuilt, republished and that fixed it.

Content Type	Original Author	Original Content on Stackoverflow
Question	KSwift87	View Question on Stackoverflow
Solution 1 - asp.net Core	Steve Tolba	View Answer on Stackoverflow
Solution 2 - asp.net Core	Jirapong	View Answer on Stackoverflow
Solution 3 - asp.net Core	Marzouk	View Answer on Stackoverflow
Solution 4 - asp.net Core	Sean Saleh	View Answer on Stackoverflow
Solution 5 - asp.net Core	MegaMilivoje	View Answer on Stackoverflow
Solution 6 - asp.net Core	mattylantz	View Answer on Stackoverflow
Solution 7 - asp.net Core	zgirod	View Answer on Stackoverflow
Solution 8 - asp.net Core	Ankush Jain	View Answer on Stackoverflow
Solution 9 - asp.net Core	Der_Meister	View Answer on Stackoverflow
Solution 10 - asp.net Core	Sydney_dev	View Answer on Stackoverflow
Solution 11 - asp.net Core	C.M.	View Answer on Stackoverflow