Test Tool: Internal Server Error: FileNotFoundException: Could not load file or assembly

It seems like I’m having an issue that I can’t see others coming across. I’ve checked everything I can think of but no matter what I do, when the lambda test tool opens in the browser, it fails to load the functions list.

In the network tab I can see:

500 Error: http://localhost:5050/webtester-api/Tester/aws-lambda-tools-defaults.json
FileNotFoundException: Could not load file or assembly 'Amazon.Lambda.Serialization.Json, Version=1.0.0.0, Culture=neutral, PublicKeyToken=885c28607f98e604'. The system cannot find the file specified.

Full Stack Trace:

System.IO.FileNotFoundException: Could not load file or assembly 'Amazon.Lambda.Serialization.Json, Version=1.0.0.0, Culture=neutral, PublicKeyToken=885c28607f98e604'. The system cannot find the file specified.

File name: 'Amazon.Lambda.Serialization.Json, Version=1.0.0.0, Culture=neutral, PublicKeyToken=885c28607f98e604'
   at System.Reflection.CustomAttribute._CreateCaObject(RuntimeModule pModule, IRuntimeMethodInfo pCtor, Byte** ppBlob, Byte* pEndBlob, Int32* pcNamedArgs)
   at System.Reflection.CustomAttribute.CreateCaObject(RuntimeModule module, IRuntimeMethodInfo ctor, IntPtr& blob, IntPtr blobEnd, Int32& namedArgs)
   at System.Reflection.CustomAttribute.GetCustomAttributes(RuntimeModule decoratedModule, Int32 decoratedMetadataToken, Int32 pcaCount, RuntimeType attributeFilterType, Boolean mustBeInheritable, IList derivedAttributes)
   at System.Reflection.CustomAttribute.GetCustomAttributes(RuntimeAssembly assembly, RuntimeType caType)
   at System.Attribute.GetCustomAttributes(Assembly element, Type attributeType, Boolean inherit)
   at System.Attribute.GetCustomAttribute(Assembly element, Type attributeType, Boolean inherit)
   at Amazon.Lambda.TestTool.Runtime.LocalLambdaRuntime.LoadLambdaFunction(LambdaFunctionInfo functionInfo) in C:\codebuild\tmp\output\src248644039\src\Tools\LambdaTestTool\Amazon.Lambda.TestTool\Runtime\LocalLambdaRuntime.cs:line 125
   at Amazon.Lambda.TestTool.Runtime.LocalLambdaRuntime.LoadLambdaFunctions(IList`1 configInfos) in C:\codebuild\tmp\output\src248644039\src\Tools\LambdaTestTool\Amazon.Lambda.TestTool\Runtime\LocalLambdaRuntime.cs:line 69
   at Amazon.Lambda.TestTool.WebTester.Controllers.TesterController.GetFunctions(String configFile) in C:\codebuild\tmp\output\src248644039\src\Tools\LambdaTestTool\Amazon.Lambda.TestTool\WebTester\Controllers\TesterController.cs:line 34
   at lambda_method(Closure , Object , Object[] )
   at Microsoft.Extensions.Internal.ObjectMethodExecutor.Execute(Object target, Object[] parameters)
   at Microsoft.AspNetCore.Mvc.Internal.ActionMethodExecutor.SyncObjectResultExecutor.Execute(IActionResultTypeMapper mapper, ObjectMethodExecutor executor, Object controller, Object[] arguments)
   at Microsoft.AspNetCore.Mvc.Internal.ControllerActionInvoker.InvokeActionMethodAsync()
   at Microsoft.AspNetCore.Mvc.Internal.ControllerActionInvoker.InvokeNextActionFilterAsync()
   at Microsoft.AspNetCore.Mvc.Internal.ControllerActionInvoker.Rethrow(ActionExecutedContext context)
   at Microsoft.AspNetCore.Mvc.Internal.ControllerActionInvoker.Next(State& next, Scope& scope, Object& state, Boolean& isCompleted)
   at Microsoft.AspNetCore.Mvc.Internal.ControllerActionInvoker.InvokeInnerFilterAsync()
   at Microsoft.AspNetCore.Mvc.Internal.ResourceInvoker.InvokeNextResourceFilter()
   at Microsoft.AspNetCore.Mvc.Internal.ResourceInvoker.Rethrow(ResourceExecutedContext context)
   at Microsoft.AspNetCore.Mvc.Internal.ResourceInvoker.Next(State& next, Scope& scope, Object& state, Boolean& isCompleted)
   at Microsoft.AspNetCore.Mvc.Internal.ResourceInvoker.InvokeFilterPipelineAsync()
   at Microsoft.AspNetCore.Mvc.Internal.ResourceInvoker.InvokeAsync()
   at Microsoft.AspNetCore.Builder.RouterMiddleware.Invoke(HttpContext httpContext)
   at Amazon.Lambda.TestTool.WebTester.Startup.<Configure>b__6_0(HttpContext context, Func`1 next) in C:\codebuild\tmp\output\src248644039\src\Tools\LambdaTestTool\Amazon.Lambda.TestTool\WebTester\Startup.cs:line 97
   at Microsoft.AspNetCore.Diagnostics.DeveloperExceptionPageMiddleware.Invoke(HttpContext context)

Has anyone come across this before or can point me in the right direction? There are no errors in the console from me running it and I’m not totally sure where it’s going wrong.

Might be worth mentioning that I’m running this on Ubuntu.

[normj]

@ericmilaneze Could you try and experiment for me and in your csproj file add the property CopyLocalLockFileAssemblies with a value of true and see if that changes your behavior?

Here is a full csproj file example.

<Project Sdk="Microsoft.NET.Sdk">
  <PropertyGroup>
    <TargetFramework>netcoreapp3.1</TargetFramework>
    <GenerateRuntimeConfigurationFiles>true</GenerateRuntimeConfigurationFiles>
    <AWSProjectType>Lambda</AWSProjectType>
    <CopyLocalLockFileAssemblies>true</CopyLocalLockFileAssemblies>
  </PropertyGroup>
  <ItemGroup>
    <PackageReference Include="Amazon.Lambda.Core" Version="1.1.0" />
    <PackageReference Include="Amazon.Lambda.Serialization.SystemTextJson" Version="1.0.0" />
    <PackageReference Include="System.Data.SqlClient" Version="4.8.1" />
  </ItemGroup>
</Project>

[judedaryl]

 <CopyLocalLockFileAssemblies>true</CopyLocalLockFileAssemblies>

Adding this worked for me. Can we add this to the README temporarily?