I'm working on a workflow for sending and email to a customer, once their order is shipped. I have created a workflow with the following conditions - record type: transaction(Item Fulfillment), event based, Events: On Create, On View or Update. Trigger Type: After Record Submit. I have a "send email" action that works when i don't set any conditions. But, in order to only send the shipped email once, i created the condition: "Shipping Status = Shipped And Old Record : Shipping Status != Shipped". This condition fails with the following error - "Error while evaluating condition: ERROR: Invalid Expression". The expression does however work on a "before Submit" workflow. Any pointers on accomplishing this would be greatly appreciated!