Here is the script of my Activation Proc:
CREATE PROCEDURE [dbo].[usp_ExecutePackage]
WITH EXECUTE AS 'dbo'
AS
BEGIN
SET ARITHABORT ON
set nocount on
set xact_abort on
DECLARE @PackageName VARCHAR(500)
DECLARE @RecvReqDlgHandle UNIQUEIDENTIFIER;
DECLARE @RecvReqMsg NVARCHAR(100);
DECLARE @RecvReqMsgName sysname;
BEGIN TRY
BEGIN TRANSACTION;
WAITFOR
(...