InvalidOperationException: Cannot find the fallback endpoint specified by route values:
When encountering the “InvalidOperationException: Cannot find the fallback endpoint specified by route values” error, it typically means that there was an issue finding the specified fallback endpoint in your application’s routing configuration.
The fallback endpoint is a catch-all endpoint that is used when no other endpoints match the requested URL. It can be useful for displaying a custom error page or redirecting to a specific route when none of the defined routes match.
Example:
Let’s assume you are working on an ASP.NET Core application, and you have set up a routing configuration in your Startup.cs file. Your routing configuration may include various endpoints, such as:
app.UseEndpoints(endpoints =>
{
endpoints.MapControllerRoute(
name: "default",
pattern: "{controller}/{action}/{id?}",
defaults: new { controller = "Home", action = "Index" });
endpoints.MapFallbackToController("Fallback", "Home");
});
In the above example, the “MapControllerRoute” method is used to define a default route for your controllers. The “MapFallbackToController” method is used to specify a fallback endpoint, which maps to the “Fallback” action in the “Home” controller.
However, if you encounter the “Cannot find the fallback endpoint specified by route values” exception, it indicates that there is an issue with the specified fallback endpoint. Ensure that the endpoint exists and is correctly configured in your routing configuration.
Verify that the fallback action and controller names are correct, and that they match the actual names defined in your application. Additionally, ensure that the fallback endpoint is not missing any required route values.
Here’s an example of a correct routing configuration with a fallback endpoint:
app.UseEndpoints(endpoints =>
{
endpoints.MapControllerRoute(
name: "default",
pattern: "{controller}/{action}/{id?}",
defaults: new { controller = "Home", action = "Index" });
endpoints.MapFallbackToController("Fallback", "Home");
});
The above configuration sets up a default route for controllers and a fallback endpoint that maps to the “Fallback” action in the “Home” controller. If none of the other routes match the requested URL, this fallback endpoint will be used.
By reviewing your routing configuration and ensuring the correctness of the fallback endpoint, you can resolve the “Cannot find the fallback endpoint specified by route values” error.