Exception Details
Server Error in '/' Application. Type XYZ was not registered in the serializer. Check that it appears in the list of configured assemblies/types to scan. Description: An unhandled exception occurred during the execution of the current web request. Please review the stack trace for more information about the error and where it originated in the code.
Solution
1. Stop the w3svc process of the website whose code you're upgrading.
2. Delete the Temporary ASP.NET Files, usually found in the folder: c:\Windows\Microsoft.NET\Framework(64)\{version}\
3. Run your application again, the exception should no longer happen.
