Steps to reproduce

1. Schedule content publication to the future.
2. Go to Calendar.
3. Select content.
4. Click on Expand sidebar button on the right.
5. Verify web browser console output.

Actual result:

JS exception occur when user click on expand sidebar button.

Uncaught TypeError: Cannot convert undefined or null to object
    at Function.values (<anonymous>)
    at Pe._isWithActiveTrigger (tooltip.js:536:19)
    at tooltip.js:268:16
    at v (index.js:254:5)
    at HTMLDivElement.r (index.js:276:5)
    at a (index.js:98:11)
    at index.js:282:7

Expected result:

No JS exception occurs.