ASP.NET Core Error: Unable to Cast 'JsonResult' to 'ContentResult'

The error message 'Unable to cast object of type 'Microsoft.AspNetCore.Mvc.JsonResult' to type 'Microsoft.AspNetCore.Mvc.ContentResult'' indicates an attempt to cast incompatible types within your ASP.NET Core application. This typically happens when you try to cast an object between two unrelated types.

To fix this, ensure you are casting to the correct type. Review the code where the casting occurs and verify that you're using the appropriate type for the cast.

For instance, if you expect a JSON result, use JsonResult instead of ContentResult:

JsonResult jsonResult = (JsonResult)result;

If you expect a content result, use ContentResult instead of JsonResult:

ContentResult contentResult = (ContentResult)result;

Always consult the documentation and examples for the specific type you are working with to understand how to handle returned results correctly in your application.