[WEB-8730] Cannot play attached MP4 videos on‑page, only download button available

The bug：

Some MP4 attachments on Mojira cannot be previewed in‑browser, only the download button shows. Certain other MP4 files can play normally.

Steps to reproduce:

1. Open an existing public Mojira issue which contains MP4 video attachments uploaded by other users.

2. View the attachments section.

Expected result:

Embedded browser video player should render, can watch MP4 directly on‑page.

Actual result:

There is only a file download link. Cannot play video inside the webpage. You must download the MP4 file locally to watch it.

Device: Mobile phone

Browser: edge

Note: Certain MP4 attachments can play successfully, while others only show download button and cannot be previewed, even with VPN.

Attachments

I truly cannot play these MP4 videos directly on‑page, downloading is the only way.

I cannot open and play this MP4 even with VPN.

Some MP4 attachments can be played normally, but some cannot.

Hello @cheenc ! Please provide a link to those bug reports where issue exists (or an issue key eg.: MC-2025), so we can reproduce it on our end.