I am trying to develop a workflow. I have multiple PDF files in a folder. I want to join each 3 files into one PDF. I have provided input array in excel and output array in excel as well. I am using read range excel activity and stored data in data table. Next I am using Get Row activity in For Each Row activity and saving input array and output array from data table to a variable to use in join PDF activity. But getting subject mentioned error. I have attached the workflow screen shots. Kindly help please.