App crashes on AppService with Could not load file or assembly, but works locally

Question

I have an ASP.NET Core 6 app deployed in Azure AppService. After I updated Serilog.AspNetCore to 7th version it started crashing with:

Could not load file or assembly 'Microsoft.Extensions.Logging.Abstractions, Version=7.0.0.0

(issue occurs only in AppService, locally everuthing works fine)

I suspect that deployment process cleans up dll's from .NET SDK similar to Azure Functions deployment flow. In Azure Functions this issue can be resolved with

<FunctionsPreservedDependencies Include="Microsoft.Extensions.Logging.Abstractions.dll" />

or

<_FunctionsSkipCleanOutput>true</_FunctionsSkipCleanOutput>

Is there something similar for AppService?

Note: After downgrading the package to 6th version, everything works fine

Note 2: I don't have access to Advanced Tools, so cannot verify what files are being deployed (restricted by my company's DevOps)

Edit: Here's my csproj

<Project Sdk="Microsoft.NET.Sdk.Web">

  <PropertyGroup>
    <TargetFramework>net6.0</TargetFramework>
    <UserSecretsId>1bcc1cf7-6fce-4196-9bb5-a7aa29a04078</UserSecretsId>
    <RootNamespace>MyApp</RootNamespace>
    <GenerateDocumentationFile>True</GenerateDocumentationFile>
  </PropertyGroup>

  <ItemGroup>
    <PackageReference Include="Microsoft.AspNetCore.Mvc.NewtonsoftJson" Version="6.0.13" />
    <PackageReference Include="Serilog.Sinks.Splunk" Version="3.7.0" />
    <PackageReference Include="Serilog.AspNetCore" Version="7.0.0" />
  </ItemGroup>

  <ItemGroup>
    <ProjectReference Include="..\MyApp.AppCore\MyApp.AppCore.csproj" />
  </ItemGroup>

</Project>

`I don't have access to Advanced Tools`. What is the App service plan you are using ? — Harshitha, May 26 '23 at 12:03
@Harshitha I use Windows P1v2 App Service plan. Added the csproj to the description — maxc137, May 26 '23 at 13:16

score 0 · Answer 1 · answered May 27 '23 at 06:57

0

I have upgraded the Serilog.AspNetCore version to 7.0.0 and able to deploy and run the Azure App service without any errors.

enter image description here

After updating the package version run and build the application to get the changes reflected in the already created bin folder.
In your Local folder check whether you have the Microsoft.Extensions.Logging.Abstractions available under Serilog.AspNetCore => Microsoft.Extensions.Logging.

enter image description here

If you don't find it, install it manually from the NuGet Package and Re-deploy the App and check.

enter image description here

Or

Try to install the package from the Extensions tab (If you have access).

enter image description here

answered May 27 '23 at 06:57

Harshitha

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Your app is targeting .NET 6 and uses Serilog (calls `.UseSerilog()` on host builder), and AppService uses .NET 6 runtime? – maxc137 May 28 '23 at 16:04
Yes..Iam using the .NET Core 6 with serilog. – Harshitha May 29 '23 at 06:59

score 0 · Accepted Answer · answered Jun 21 '23 at 04:40

Turns out it wasn't App Service's fault, but .NET publishing (when publishing multiple project it messes up dependency versions sometimes):

Solution in my case was to add <IsPublishable>false</IsPublishable> to all test projects. Foolproof way of doing it is to add Directory.Build.targets file containing this to the repository's root:

<Project>

  <PropertyGroup Condition="'$(IsTestProject)' == 'true'">
    <IsPublishable>false</IsPublishable> <!-- Workaround for https://github.com/dotnet/sdk/issues/11953#issuecomment-770434716. Try removing after .NET 8 migration -->
  </PropertyGroup>

</Project>

App crashes on AppService with Could not load file or assembly, but works locally

2 Answers2