VS2012: Release vs Debug

Question

There is an Azure Cloud service with webrole project developed in ASP.NET MVC 4 and JQuery. When the cloud service is deployed with Debug build, everything works fine.
But Release build has UI issues and also some exceptions like:

Error: Message: The ViewData item that has the key 'XyzID' is of type 'System.Int32' but must be of type 'IEnumerable'. Exception Name: System.InvalidOperationException: The ViewData item that has the key 'XyzID' is of type 'System.Int32' but must be of type 'IEnumerable'.

What could be the reasons?

Answer 1

The most common reason for this is conditional compilation sections. Look for sections marked like

#if DEBUG

#if RELEASE

In fact try to run the project locally with different build configuration such as Debug, Release, Cloud etc and you may be able to reproduce the issue.