I am trying to copy details of the details of the default cart to other custom named draft cart that is later to be accessed. I can successfully copy the details manually, but as I initially tried to run the CartValidate workflow for calculating totals, I got an error:

[KeyNotFoundException: The given key was not present in the dictionary.]
Mediachase.Commerce.Website.Helpers.CartHelper.RunWorkflow(String name) +375

Following is an example which causes the error:

var draftName = "draft";

var currentCartHelper = new CartHelper(Cart.DefaultName);
var currentCartDecorator = new CartDecorator(currentCartHelper.Cart);
var newCartHelper = new CartHelper(draftName);
var newCartDecorator = new CartDecorator(newCartHelper.Cart);

foreach (var lineItem in currentCartHelper.GetOrderForm().LineItems)
{
    newCartHelper.GetOrderForm().LineItems.Add((LineItem)lineItem); 
}

...
Other property setups...
...

newCartHelper.Cart.RunWorkflow(OrderGroupWorkflowManager.CartValidateWorkflowName);
newCartHelper.Cart.AcceptChanges();

The execution crashes on

newCartHelper.Cart.RunWorkflow after all the workflow activities have been done successfully.

I managed to the copy all the details manually, but I'd like to if you can run the cart validation against some custom cart?

And what is the dictionary that is throwing the KeyNotFoundException?

Or what is the suggested way of doing this copying?

Any help is appreciated.