Cannot edit or remove tabs

Problem/Motivation

Attempting to remove or rename a tab results in an error and the tabs are not removed/renamed.

Steps to reproduce

Add tabs to a page or edit a page with existing tabs

Click on the tab to bring up the "Set tab title" widget

Attempt to rename the tab and click the green tick

Attempt to remove the tab with the eraser icon

The tabs aren't removed/renamed and there is a console error:

Uncaught CKEditorError: selectedElement is null in /bootstraptabsrenametabcommand.js?:32

Interestingly this only happens if there are contents within the actual tab, if it is completely empty -- it lets you edit/remove it -- so before #3398404 newly added tabs to an existing set would have it still work on those newly added tabs.

Sorry I couldn't see how to fix just yet but will endeavor to tackle later if not sorted :)