Disappearing Editor Tabs

I seem to be experiencing an issue where tabs are disappearing from the editor. For example, when I click data, all the relevant horizontal tabs show like Tables, Columns, Slices, & User-Settings. However, when I click one of those horizontal tabs, nothing is shown and the tabs disappear.

I am experiencing this with Firefox and MS Edge.

This is a known problem.

A fix is coming.

The problem seems to be caused when a table is removed but slices remain that use the removed table. Try reloading the editor, re-add the table temporarily, remove the slices that use it, then remove the table again.