SQL Server Agent 2012 Passing Paramaters

Hey

I have an SSIS package with one Parameter , Destination (string)

SQL Server Agent 2012 

Using SQL server Agent under [Job Step] --> [set Values] I have set the

[Property Path] --  \Package.Variables[User::Destination].Properties[Value]

[Value] -- C:\Work\Test.xlsx

When I run the Job I get a generic error

   Code: 0x00000001
   Source: Script Task
   Description: Exception has been thrown by the target of an invocation.

1. Any tips on how to Debug?
2. Is the [Parameters] tab released yet for SQL server Agent 2012? We are running build 11.0.3000.0 , Service Pack 1

http://www.bidn.com/blogs/MikeDavis/ssis/1566/sql-2011-denali-new-ssis-parameters