You have enabled the generation of the Google Shopping XML Product Review feed in the settings of the plugin. However, no XML file is created. The folder is empty and when you try to access the URL of the XML feed in a browser, error 404 (not found) is shown. This problem could be caused by multiple reasons that we discuss below.
File system permissions
This problem is most likely caused by the missing 'write' permission for the folder where the plugin saves the XML feed. Please make sure that WordPress has the permission to create and change files in the folder where the plugin saves the XML feed. After you added the missing permissions in the file system of your web server, re-save the settings in the plugin to re-generate the XML feed.
Learn more about WordPress file permission here.
No products in the XML feed
Another reason of this problem could be that there are no products eligible to be included in the XML feed. The plugin offers option to exclude specific products or entire categories of products from the XML product feed. If all product categories or products are excluded, no XML product feed will be created.
Please remove all the exclusion rules and then re-save the settings in the plugin to re-generate the XML feed.