ASP.NET Core 6 MVC - The view 'Index' was not found - asp.net-core

Question

I can run my asp.net 6 mvc app in VS2022 with no issues. When I publish to a folder and deploy to IIS or run the exe myself I get an error 'the view Index was not found'.
The search locations reported are correct. My views are in the correct folder.
I have also added Microsoft.AspNetCore.Mvc.Razor.RuntimeCompilation nuget package and updated Program.cs:
builder.Services.AddControllersWithViews().AddRazorRuntimeCompilation();
The *.cshtml files Build Action are set to Content in Visual Studio.
Nothing suggested in various stackoverlow posts resolves the issue. The majority are related to a VS2022 issue requiring Microsoft.AspNetCore.Mvc.Razor.RuntimeCompilation package to be added.
I've set stdoutLogEnabled="true" and verified the log generated when running through IIS matches the log output when calling the .exe. I don't believe this is an IIS issue.
Below is my Program.cs:
var builder = WebApplication.CreateBuilder(args);
// Add services to the container.
builder.Services.AddControllersWithViews().AddRazorRuntimeCompilation();
builder.Services.AddDistributedMemoryCache();
builder.Services.AddHttpContextAccessor();
var app = builder.Build();
app.UseExceptionHandler("/Home/Error");
app.UseStatusCodePagesWithReExecute("/Home/Error", "?code={0}");
app.UseStaticFiles();
app.UseRouting();
app.UseAuthorization();
app.MapControllerRoute(
name: "default",
pattern: "{controller=Home}/{action=Index}/{id?}");
app.Run();
Nothing of interest in appsettings.json:
{
"Logging": {
"LogLevel": {
"Default": "Information",
"Microsoft.AspNetCore": "Warning"
}
},
"AllowedHosts": "*"
}
The project file is as follows:
<Project Sdk="Microsoft.NET.Sdk.Web">
<PropertyGroup>
<TargetFramework>net6.0</TargetFramework>
<Nullable>enable</Nullable>
<ImplicitUsings>enable</ImplicitUsings>
<RootNamespace>MyFirstApp.MVC</RootNamespace>
</PropertyGroup>
<ItemGroup>
<PackageReference Include="Dapper" Version="2.0.123" />
<PackageReference Include="Microsoft.AspNetCore.Mvc.Razor.RuntimeCompilation" Version="6.0.10" />
<PackageReference Include="Microsoft.Data.Sqlite" Version="7.0.2" />
<PackageReference Include="System.Data.SqlClient" Version="4.8.4" />
<PackageReference Include="System.DirectoryServices.AccountManagement" Version="6.0.0" />
</ItemGroup>
<ItemGroup>
<Folder Include="wwwroot\images\" />
</ItemGroup>
</Project>
Below is the error log. Logging added to confirm Controller action method is completing with no error:
info: Microsoft.Hosting.Lifetime[0]
Application started. Press Ctrl+C to shut down.
info: Microsoft.Hosting.Lifetime[0]
Hosting environment: Production
info: Microsoft.Hosting.Lifetime[0]
Content root path: D:\Projects\ReportViewer
**info: ReportViewer.MVC.Controllers.HomeController[0]
Into Index**
**info: ReportViewer.MVC.Controllers.HomeController[0]
About to return view Index**
fail: Microsoft.AspNetCore.Mvc.ViewFeatures.ViewResultExecutor[3]
The view 'Index' was not found. Searched locations: /Views/Home/Index.cshtml, /Views/Shared/Index.cshtml
fail: Microsoft.AspNetCore.Diagnostics.ExceptionHandlerMiddleware[1]
An unhandled exception has occurred while executing the request.
System.InvalidOperationException: The view 'Index' was not found. The following locations were searched:
/Views/Home/Index.cshtml
/Views/Shared/Index.cshtml
at Microsoft.AspNetCore.Mvc.ViewEngines.ViewEngineResult.EnsureSuccessful(IEnumerable`1 originalLocations)
at Microsoft.AspNetCore.Mvc.ViewFeatures.ViewResultExecutor.ExecuteAsync(ActionContext context, ViewResult result)
at Microsoft.AspNetCore.Mvc.ViewResult.ExecuteResultAsync(ActionContext context)
at Microsoft.AspNetCore.Mvc.Infrastructure.ResourceInvoker.<InvokeNextResultFilterAsync>g__Awaited|30_0[TFilter,TFilterAsync](ResourceInvoker invoker, Task lastTask, State next, Scope scope, Object state, Boolean isCompleted)
at Microsoft.AspNetCore.Mvc.Infrastructure.ResourceInvoker.Rethrow(ResultExecutedContextSealed context)
at Microsoft.AspNetCore.Mvc.Infrastructure.ResourceInvoker.ResultNext[TFilter,TFilterAsync](State& next, Scope& scope, Object& state, Boolean& isCompleted)
at Microsoft.AspNetCore.Mvc.Infrastructure.ResourceInvoker.InvokeResultFilters()
--- End of stack trace from previous location ---
at Microsoft.AspNetCore.Mvc.Infrastructure.ResourceInvoker.<InvokeNextResourceFilter>g__Awaited|25_0(ResourceInvoker invoker, Task lastTask, State next, Scope scope, Object state, Boolean isCompleted)
at Microsoft.AspNetCore.Mvc.Infrastructure.ResourceInvoker.Rethrow(ResourceExecutedContextSealed context)
at Microsoft.AspNetCore.Mvc.Infrastructure.ResourceInvoker.Next(State& next, Scope& scope, Object& state, Boolean& isCompleted)
at Microsoft.AspNetCore.Mvc.Infrastructure.ResourceInvoker.InvokeFilterPipelineAsync()
--- End of stack trace from previous location ---
at Microsoft.AspNetCore.Mvc.Infrastructure.ResourceInvoker.<InvokeAsync>g__Awaited|17_0(ResourceInvoker invoker, Task task, IDisposable scope)
at Microsoft.AspNetCore.Mvc.Infrastructure.ResourceInvoker.<InvokeAsync>g__Awaited|17_0(ResourceInvoker invoker, Task task, IDisposable scope)
at Microsoft.AspNetCore.Routing.EndpointMiddleware.<Invoke>g__AwaitRequestTask|6_0(Endpoint endpoint, Task requestTask, ILogger logger)
at Microsoft.AspNetCore.Session.SessionMiddleware.Invoke(HttpContext context)
at Microsoft.AspNetCore.Session.SessionMiddleware.Invoke(HttpContext context)
at Microsoft.AspNetCore.Authorization.AuthorizationMiddleware.Invoke(HttpContext context)
at Microsoft.AspNetCore.Diagnostics.StatusCodePagesMiddleware.Invoke(HttpContext context)
at Microsoft.AspNetCore.Diagnostics.ExceptionHandlerMiddleware.<Invoke>g__Awaited|6_0(ExceptionHandlerMiddleware middleware, HttpContext context, Task task)
fail: Microsoft.AspNetCore.Mvc.ViewFeatures.ViewResultExecutor[3]
The view 'Error' was not found. Searched locations: /Views/Home/Error.cshtml, /Views/Shared/Error.cshtml
fail: Microsoft.AspNetCore.Diagnostics.ExceptionHandlerMiddleware[3]
An exception was thrown attempting to execute the error handler.
System.InvalidOperationException: The view 'Error' was not found. The following locations were searched:
/Views/Home/Error.cshtml
/Views/Shared/Error.cshtml
I'd really appreciate any suggestions you may have.
Thanks,
Lance

Answer 1

Turns out the publish step in VS was failing to resolve some MVC Analyser dlls. Despite this, it was still reporting the publish succeeded and generated the dlls and exe files.
Only spotted the publishing issue after scrolling through the publish output log for any clues.
Publishing problem was caused by having two versions of .NET6 installed on the dev machine. I removed the older version and updated dotnet environment variables to point to dotnet6 located in C:\Program Files....that broke the Dependency Frameworks in the MVP Project. The Path and Version entries were blank for Microsoft.AspnetCore.App and Microsoft.NETCore.App.
Under time pressure so created a new MVC project, copied all files across to this new project, published and deployed to IIS with no issues.