When no file is generated, it can mean one of two things.
1) Your campaign is running on a schedule. (No files are generated when the campaign is running on automation)
2) There is no file to show since no items were created. (This can mean that the filter of the campaign is not allowing any items to be created, or your feed is empty)
* The only time a file appears in the Submission Results is when a job is submitted manually. If you would like the submission breakdown of an automatic job run, you can rerun the same job and save the target to file.