The Text pane, the right side of any document window tab, has 3 sub-tabs with 'Text' being the default selection. As many Tinderbox projects don’t need to export HTML at all, these controls are hidden by default. Use the Window menu ▸ Shown/Hide Text Pane Selector will toggle the visibility of these sub-tabs.
From v7.2.0, the ordering of the tabs is changed from Text/HTML/Preview to Text/Preview/HTML. This reflects the ability to use preview as an internal viewer without necessarily exporting.
When first opening the document, if the text pane selector is initially hidden, hiding it is deferred slightly to allow seeing it sliding away, helping to confirm that it is deliberately hidden (and suggesting that there is a way to recover it).
The sub-tabs are: