Specify file path for cron?

Where/how do you specify the file path for the cron? Every time a report is sent, it tells me "no file path was specified". If I click on the cron URL in the backend, it says it was triggered but no file path was specified.

The first time I activated the cron for this site, back in April, it worked perfectly fine, then when I updated the Google Merchant .xml file yesterday, I've been having these problems.

Any help or suggestions would be greatly appreciated.

Thanks!