I have a workflow in which I need to make 3 FTP file pulls using the download tool, then union the data from all 3 pulls together. Occasionally, one of the files does not exist, which means that data stream produces an error. When this happens, none of the data from the other 2 functioning data streams go through the union tool.
How can I ensure that data from all present files still goes through the union tool when one of the 3 download tools produces an error?