i am getting below exception when i try to execute my asp.net mvc 5 application.
see the exception please.
An exception of type 'System.ArgumentException' occurred in System.Web.Mvc.dll but was not handled in user code Additional information: Return type 'System.String' is not supported
Please provide code.
First, please try to create a new MVC project and run it to check whether it works fine.
Secondly, please use this command to install or update MVC package:
Install-Package Microsoft.AspNet.Mvc -Version 5.1.1
If you still have the issue, please share the project on the OneDrive.