Permalink of image showing 404 error

Hi,

This plugin is awesome, I really needed to use it! It works for what I needed but it shows a 404 error on my permalink for my images in the media library. The URL it points to is good so it is not a real big issue but just wondering if there is a way to fix this. It does not do this if I only use the $post_id or post_name.
The tags I used are:

/examplecustomposttype/%postname%/%author%/%year%/%monthnum%

Any suggestions to make this not show the 404 error when clicking the permalink in the media library would be great! Again the front end of the site works but just not sure if the 404 would cause SEO issues.

Thank you!