Top Menu Dropdown Does not Work in IE 11

Summary

Top menu dropdown (Projects, Issues and Dashboards) does not work in IE 11. It only shows a small shadow below when you click it.
ie11.png

Environment

IE 11 browser

Steps to Reproduce

1. Create an issue
2. Upload a Word document
3. Copy the browser URL and close the IE browser
4. Reopen the IE browser
5. Paste URL into address bar and login again
6. Attempt to download the Word document
7. Click on the top menu dropdown (Projects, Issues and Dashboards)

Expected Behaviour

The dropdown menu will show the contents

Actual Behaviour

It only shows a small shadow below the menu bar and doesn't display the options.

Notes

• Boards dropdown works
• Refreshing the browser fixes the issue
• Tested with IE 11.540.15063.0

Workaround

Use a browser other than IE.