Package connection error

Question

I created a project . the 4 packages uses same project connection to the ole db, and each has a package connection to the excel file it is supposed to import from c drive. the packages works well on the ssis platform and imports it into the engine, but when
used in sql server agent service, it does not work and gives the error below. 
Executed as user: USER-PC\SYSTEM. 
Microsoft (R) SQL Server Execute Package Utility  
Version 11.0.2100.60 for 32-bit  Copyright (C) Microsoft Corporation. All rights reserved.  
  Started:  11:50:16  Error: 2015-01-08 11:50:16.29     Code: 0xC001000E    
 Source: Package      Description: The connection "{D16EBEF0-87BB-4062-8512-0844538E99F5}" is not found.
 This error is thrown by Connections collection when the specific connection element is not found. 
 End Error  Error: 2015-01-08 11:50:16.34     Code: 0xC001000E     Source: Package     
 Description: The connection "{D16EBEF0-87BB-4062-8512-0844538E99F5}" is not found. 
This error is thrown by Connections collection when the specific connection element is not found. 
 End Error  Error: 2015-01-08 11:50:16.34     Code: 0xC004800B     Source: Data Flow Task SSIS.Pipeline  
   Description: Cannot find the connection manager with ID "{D16EBEF0-87BB-4062-8512-0844538E99F5}" 
in the connection manager collection due to error code 0xC0010009. That connection manager is needed by
 "OLE DB Destination.Connections[OleDbConnection]" 
in the connection manager collection of "OLE DB Destination". Verify that a connection manager
 in the connection manager collection, Connections, has been created with that ID.
  End Error  Error: 2015-01-08 11:50:16.34     Code: 0xC0047017     
Source: Data Flow Task SSIS.Pipeline     
Description: OLE DB Destination failed validation and returned error code 0xC004800B. 
 End Error  Error: 2015-01-08 11:50:16.34     Code: 0xC004700C    
 Source: Data Flow Task SSIS.Pipeline    
 Description: One or more component failed validation.  
End Error  Error: 2015-01-08 11:50:16.34     Code: 0xC0024107     Source: Data Flow Task     
 Description: There were errors during task validation.  
End Error  DTExec: The package validation returned DTSER_FAILURE (1)
i will appreciate your contributions. the project runtime is set to false as well. or do i have to do that for individual package

Answer 1

Did you change the deployment type to package recently?
+1
Since you can see the errors in the job history, it means you scheduled the package like in the package deployment model, i.e. without using the catalog. Like this, you cannot use project connections.
MCSE SQL Server 2012 - Please mark posts as answered where appropriate.