Unable to download attachments that contain HTML-unsafe characters in their file name

Summary

Unable to download attachments that contain an ampersand, omega or whatever special characters in HTML in their filename (like &, for example).

Steps to Reproduce

1. Add an attachment with filename that contains ampersand to a space
2. From the attachments page click on the filename

Expected Results

• File is downloaded

Actual Results

• 'Page Not Found' is loaded

Workaround

• Rename filename to remove ampersands