Issue Summary

If we open an issue with attachments, the attachments are intermittently not rendered correctly. 

Steps to Reproduce

1. Go to any issue in Jira
2. Add an attachment in Description / Directly an attachment

Expected Results

The attachments should be rendered correctly 

Actual Results

The attachment preview says "Preview unavailable"

Workaround

This issue is intermittent and seems to resolve upon a lot of browser refresh.