If only file uploads are enabled for the workshop submission then if example submissions are uploaded by a teacher, the files do not save. No error is shown to the user.

Confirmed in 4.3.8 and 4.5 (qa.moodle.et)

1. Create a course
2. create a workshop activity
   1. submission settings: File attachment only
   2. Example submissions: enabled (assessment of example submissions is voluntary)
3. all other settings can be left as default
4. in the setup phase:
5. edit assessment form and add 2 criteria
6. Add example submission
7. save and close and observe no error. The example submission entry is shown
8. click "assess" and see that the uploaded file is missing.