Microsoft.AspNetCore.Mvc.ViewEngines.ViewEngineException – The view ‘xyz’ was not found

The Microsoft.AspNetCore.Mvc.ViewEngines.ViewEngineException – The view 'xyz' was not found exception occurs in ASP.NET Core when the MVC framework attempts to render a view, but it cannot locate the view file that matches the name specified in the controller action.

Complete Information About Microsoft.AspNetCore.Mvc.ViewEngines.ViewEngineException – The view 'xyz' was not found

1. What is the ViewEngineException Error?

The ViewEngineException is thrown when ASP.NET Core’s MVC framework cannot find the view that corresponds to the name specified in the controller action. In ASP.NET Core, views are typically located in the Views folder, and they need to match the names provided in controller actions.

For example, if a controller action tries to return a view with the name "xyz", but no view file named xyz.cshtml exists in the appropriate location, this exception will be thrown.

2. Common Causes of the Error

The ViewEngineException with the message “The view ‘xyz’ was not found” can be caused by several issues, including:

• View File Missing: The specified view file (e.g., xyz.cshtml) does not exist in the expected folder (such as Views/ControllerName/ or Views/Shared/).
• Incorrect View Name: The name of the view provided in the View() method is incorrect or does not match the actual file name (case sensitivity can be a factor on some operating systems).
• Incorrect Folder Structure: The view might exist, but it is placed in an incorrect folder (for example, in a different controller’s folder or in the wrong directory).
• View Not Registered in the Right Location: If you’re using custom view locations, the view might not be registered in the location where the MVC engine expects to find it.
• Missing or Incorrect return View() Call: The View() method might be missing or incorrectly called in the controller. If the view name is explicitly passed to View(), it should match the actual view file.
• Shared Views: If the view is intended to be a shared view (e.g., in Views/Shared/), but the controller does not reference the shared location correctly.

3. How the Error is Presented

The error message for this exception typically looks like this:

Microsoft.AspNetCore.Mvc.ViewEngines.ViewEngineException: The view 'xyz' was not found.

This indicates that the MVC framework could not locate a view file matching the specified name (xyz) in the appropriate location.

4. How to Troubleshoot and Resolve the Error

To troubleshoot and resolve the ViewEngineException – The view 'xyz' was not found error:

• Verify the View File Exists: Check if the view file xyz.cshtml exists in the correct location (e.g., Views/ControllerName/xyz.cshtml or Views/Shared/xyz.cshtml).
• Check for Typos in the View Name: Ensure that the view name specified in the controller action is correct and matches the actual file name exactly (case-sensitive).
• Confirm Folder Structure: Make sure the view is placed in the appropriate controller folder. For example, if you are trying to return a view in HomeController, the view should be located in Views/Home/.
• Use Explicit Path for Shared Views: If the view is in the Views/Shared/ folder, ensure you reference it correctly in the controller, such as return View("Shared/xyz") if the view is in the Shared folder.
• Check View() Method Usage: If you are passing a string to the View() method, ensure that the name provided is correct. You can also pass the full path if needed: return View("xyz"); // Correct view name return View("~/Views/Shared/xyz.cshtml"); // Full path to shared view
• Check Custom View Locations: If your application is using custom view locations, ensure that the view is located in one of those custom directories. You may need to configure the RazorViewEngineOptions in Startup.cs to add custom view locations.

Example to add custom view location in Startup.cs:

public void ConfigureServices(IServiceCollection services)
{
    services.AddControllersWithViews()
            .AddRazorOptions(options =>
            {
                options.ViewLocationFormats.Add("/CustomViews/{1}/{0}.cshtml");
            });
}

5. Example of the Error in Code

Here’s an example of a controller action that would trigger this error:

public IActionResult Index()
{
    return View("xyz"); // Looking for "Views/Home/xyz.cshtml" or "Views/Shared/xyz.cshtml"
}

If there is no xyz.cshtml file in the expected locations (Views/Home/ or Views/Shared/), the exception will be thrown.

6. Why is This Error Important?

The ViewEngineException – The view 'xyz' was not found error is crucial to resolve because it prevents the application from rendering the intended view to the user. If views are missing or misconfigured, the application will fail to return the appropriate HTML, resulting in a poor user experience and broken functionality.

7. Preventing the Error

To prevent this error:

• Always Ensure Views Exist: Make sure that for every action method that returns a view, a corresponding view file exists in the correct folder.
• Follow Naming Conventions: Ensure that view names match exactly, including case sensitivity, with the file names.
• Use Correct Folder Structure: Place views in the correct folder corresponding to the controller’s name.
• Handle Shared Views Properly: For shared views, ensure that the Views/Shared/ folder is used, and the view name is referenced correctly in the controller.

---