File Not Found Error

The error is not related to the plugin.
A quick Google search shows similar problems due to browser extensions, WordPress caching plugins or server configuration. The following forum threads may be of interest.

https://www.ads-software.com/support/topic/exporting-wp-error-6-neterr_file_not_found?replies=4#post-3914307

https://www.ads-software.com/support/topic/plugin-wp-download-codes-new-webpage-is-not-found-error?replies=2#post-2890614

https://www.ads-software.com/support/topic/blog-export-errors-due-to-jetpack-plugin?replies=1

https://www.ads-software.com/support/topic/plugin-download-protect-dp-stopped-working-on-some-files-still-works-with-others?replies=2

Thank you. I think I am having a permissions issue on my site. Can you tell me where in the directory structure your plugin creates the csv file to be downloaded?

It doesn’t create a file. It echoes the content directly and adds http headers so that browsers download it as a file.