JIRA Backup Manager result isn't showing up on IE11

Summary

Completed backup export zip file isn't showing up in IE11. Instead, "Please wait..." is written.

Environment

JIRA Cloud (JIRA v1000.962.0)

Steps to Reproduce

1. Go to JIRA Backup Manager
2. Create a Backup without attachment (so that you get fast result)

Expected Results

"Site Backup.zip" download link should be visible once the export has completed

Actual Results

"Please wait..." is written on the screen. When checked in console, the following error can be seen:

Notes

It only affects IE11. The download link can be seen if the page is opened through Google Chrome

Workaround

At the moment, try opening the page through another browser such as Google Chrome or Mozilla Firefox