Sprint Burndown gadget does not load any data

Summary

Sprint Burndown gadget does not load any data on the dashboard.
Sometimes it's possible to make it load, but it's intermittent and doesn't seems to have anything else related.

Environment

• JIRA 7.0.0-OD-08-002

Steps to Reproduce

1. Add Sprint Burndown gadget to the dashboard
2. In gadget's configuration, select the board with the current active Sprint and refresh interval is 15 minutes, Save.

Expected Results

The gadget should load the data

Actual Results

The gadget does not load any data (blank)

Workaround

1. If you are the owner of the Dashboard: Click Edit -> Cancel on the gadget configuration.
2. If you are not, you can either:
   • Copy that dashboard and then click Edit -> Cancel button Or
   • Ask the owner of the board to change the Refresh Interval of the gadget to 15 minutes, the data will be loaded after 15 minutes.

Notes:
This happens mainly on Google Chrome, also verified in Safari and IE.
Firefox can be used instead.