I would like to restore a heading number that I deleted. I tried pressing Shift+Backspace with the cursor at the beginning of the heading, as suggested in Chapter Numbering, but it did not work. For information, I turned on the numbering through Tools > Chapter numbering > Level 1.
I am using LibreOffice Version 7.2.2.2 on a Mac M1 (Big Sur Version 11.6).
Maybe Number: is set to None (menu Tools - Chapter numbering - Numbering tab). Change it to 1, 2, 3, ….
Thank you @LeroyG. I set the Number to ‘1, 2, 3, …’ and successfully numbered several headings (all Heading 1, which I’m using as chapter headings). I then deleted one of the numbers and now cannot restore it.
Shift+Backspace works for me on Windows 10 & LO 7.1.5.2 even after other operations in the document.
If desperation strikes, the direct way would be to apply paragraph style Text Body to the heading, then apply Heading 1 style.