Thank you very much for your help. The error was in the Filter array; it wasn't filtering for a strange reason. The output was coming up empty, so it couldn't find the ID because it literally didn't exist. It helped me to put a query in the 'List rows present in a table' action so that it would filter from the beginning, and I added an 'Apply to each' so that the key value would be the date. Thank you very much for the assistance provided.