I put the cursor at the line above the first heading in the page. Then insert TOC. The inserted TOC is shown as
When I click the edit icon, a page opens and I see the following error.
Error rendering macro 'toc' : [com.ctc.wstx.exc.WstxLazyException] com.ctc.wstx.exc.WstxParsingException: Duplicate attribute 'src'. at [row,col {unknown-source}]: [1,8560]