jakewisener on "[Plugin: WP-Filebase Download Manager] 404 not found"

I am experiencing a 404 error of the following:

"Not Found

The requested URL /download/02-04-2007-kNOw-Fear-Fear-of-God_2.pdf was not found on this server.

Additionally, a 404 Not Found error was encountered while trying to use an ErrorDocument to handle the request."

I haven't had this problem before. How might I go about fixing it?

https://wordpress.org/plugins/wp-filebase/