UserAgent: Mozilla/5.0 (Macintosh; Intel Mac OS X 10_12_6) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/60.0.3112.90 Safari/537.36

Steps to reproduce the problem:
1. Select Bookmarks menu.
2. Select Other Bookmarks
3. Select third level submenu
4. Right click

What is the expected behavior?
Pop-up menu should appear.  "Open.  Open all.  Open in new window.  Open in incognito window." etc.

What went wrong?
Pop-up menu no longer appears as it used to.

Did this work before? Yes 

Chrome version: 60.0.3112.90  Channel: n/a
OS Version: OS X 10.12.6
Flash Version: