Here is how to reproduce this issue:
1. Create a syllabus
2. Click on "Add attachments" button to go to Resource tool
3. Add a file whose name contains any foreign character. For example, à.jpg.
4. If you click on the link of this file in Resource tool, you will be able to view it.
5. Click on "Continue" button to come back to Syllabus tool
5. Go to Preview page. If you click on the file link here, you will get a 404 error.
I will attach a sample file here. Thanks.