Combo action works from deck view but not in a workflow

[Lucinda_Mason]

I am copying rows from one spreadsheet to another through my app. Basically importing them and adding the column values as needed.

This works as an action on a view. I use it in a combined action, image #3.

This works as well. I use it in a combined action, image #3.

This is the combined action. Works perfectly from a deck view. But it won’t work when called from a Report.

My report settings.

Log Error: “Errors”: “Error: ‘Execute a Sequence of Actions’ Grouped action ‘ComboCopyDonorRequestsSetAdded’ child action ‘CopyDonorToRequests’ failed due to error: Error: Perform DataAction ‘CopyDonorToRequests’ failed because Row having key ‘8715fb8e’ in table ‘Requests’ in field ‘START_DATE’ is required to have a value. \nError: ‘Add Row’ Data action ‘CopyDonorToRequests’ failed with exception Collection was modified; enumeration operation may not execute. .”,

All the rows in the copy FROM table have a value in [Date Added] which is copied to [START_DATE] so I don’t understand the error. What am I missing?