What version are you running?
Operating System: Ubuntu 18.04

Review Board: 3.0.15

MySQL Version: 5.7.28

Memcached Version: 1.5.6
What's the URL of the page containing the problem?
https://reviewboard/r/new/

https://reviewboard/r/$ID/ (where $ID is the if of the draft review request)
What steps will reproduce the problem?

Go to New Review Request page: https://reviewboard/r/new/
Click (None - File attachments only).
Click Create.
Upload a file. After completing the upload, the file does not appear in UI.
Upload another file under a different name. After completing the upload, neither file appears in UI.
Discard the review. Both files now appear in the UI.


What is the expected output? What do you see instead?
The files should be visible in the UI as they are uploaded.
What operating system are you using? What browser?
Windows 10 (Chrome/Firefox)

Ubuntu 18.04 (Chromium/Firefox)
Please provide any additional information below.