I have a IIS 10.0 server that everything is working fine, with one issue. Any .pdf file returns 404. I know permissions are correct as all the image files in the same folder are working fine.
The PDF mime type exists in both the IIS root and the site and there is no Request filtering set.
Most the results on the web are for an older version of IIS, so I am out of ideas. Anyone else run into this?