SCSM 2012 - Problems running script in custom workflow

Question

Hi all,
I'm trying to create a custom workflow in the Authoring Tool that will send an email when a ticket in certain queues is unassigned, but I only want this to run during business hours. I've created the PowerShell script, and it runs great on its own.
However, whenever I try to add any kind of scripting event to a custom workflow, the workflow fails:
Microsoft.EnterpriseManagement.Common.InconsistentDataException: The requested objects had an unknown management pack. ---> Microsoft.EnterpriseManagement.Common.InconsistentDataException: The call produced inconsistent results. The data on the client
does not match the data returned from the server. The most likely cause is that client-side cache is out of sync with server data. ---> Microsoft.EnterpriseManagement.Common.ObjectNotFoundException: An object of class ManagementPack with ID %GUID% was not
found...
If I create and import a management pack with an empty workflow, the workflow succeeds. If I use the "Add AD DS User to Group", the workflow succeeds. But as soon as I add a scripting event, the workflow fails.
For testing, I added a PowerShell event with this code: 
$a=1
I also added a Command Script event with this code and got the same error as above: ping SomeServer
I even tried a VBScript, but that caused the workflow to not run at all:
dim someVariable
someVariable = "some value"
I then disabled the VBScript activity and the workflow runs successfully.
I'm running SCSM 2012 SP1 with UR4. I am copying the .dll file into the SCSM installation directory (which is not in the default location). The GUID referenced in the error code is the GUID for my custom MP.
This is my first time creating a custom workflow in the Authoring Tool. Can you tell me what I'm missing? Please let me know if you need any more information
Thanks!
Marnie

Answer 1

Thanks, Anders. I had seen that issue in my searches on this problem. I had tried both the manual fix suggested in that post as well as upgrading to UR4 (so I'm on on SP1 UR4). Neither approach made any difference.
Am I supposed to do anything with the .cs, .xoml, and .xomlx files that also get generated? I noticed that if I move ALL the associated files into the install directory (not just the .dll file), then import the MP, I get a different error. Instead of the
MP being missing, the error is now:
System.NullReferenceException: Object reference not set to an instance of an object.
   at Microsoft.ServiceManager.WorkflowAuthoring.ActivityLibrary.WindowsPowerShellScript.Activity_Closed(Object sender, ActivityExecutionStatusChangedEventArgs e)
   at System.Workflow.ComponentModel.ActivityExecutorDelegateInfo`1.ActivityExecutorDelegateOperation.Run(IWorkflowCoreRuntime workflowCoreRuntime)
   at System.Workflow.Runtime.Scheduler.Run()
This makes it seem like I do need to move ALL the files to the install directory, but maybe now the workflow just doesn't like my code?
Thanks!
Marnie