Can't add/delete gadgets on a dashboard when using IE11

Summary

Can't add/delete gadgets on a dashboard when using IE11

Environment

This bug only affects cloud version. I couldn't reproduce this bug on server version. (JIRA 7.2.3)

Steps to Reproduce

• Scenario 1
  1. Click Add gadget on a dashboard
  2. Select a gadget and put Add gadget button on the dialog

• Scenario 2
  1. Try to delete a gadget from a dashboard

Expected Results

We should be able to add/delete gadgets correctly as we can do them with other browsers.

Actual Results

• Scenario 1 : There is no response from JIRA when I put Add gadget button and the gadget was not added to the dashboard
  
• Scenario 2 : The following error was shown
  

Notes

• As I mentioned above, I couldn't reproduce this bug with other browsers than IE

Workaround

Please use other browsers instead of IE.