The following example fails with recent betas, but not with TL18: \setupinteraction [state=start] \setuptagging [state=start] \setupbackend [export=yes,xhtml=yes] \setupexport [title={Title}] \setupstructure [state=start] \starttext \startchapter[title={Chapter title}] \startparagraph Chapter introduction. \stopparagraph \startsection[title={Section 1 title}] \startparagraph Section one text. \stopparagraph \stopsection \startsection[title={Section 2 title}] \startparagraph Section two text. \stopparagraph \stopsection \startsection[title={Section 3 title}] \startparagraph Section three text. \stopparagraph \stopsection \startsection[title={Section 4 title}] \startparagraph Section four text. \stopparagraph \stopsection \startsection[title={Section 5 title}] \startparagraph Section five text. \stopparagraph \stopsection \startsection[title={Section 6 title}] \startparagraph Section six text. \stopparagraph \stopsection \startsection[title={Section 7 title}] \startparagraph Aaaa aaaaa aa aaaaaaa (aa aaaaaa) aaaaaaaa, aaa aa aaa aaaa aaaa aaaa aaaa aaa aaaaaaaaaa aa aaaaaaaa aaaa aaaa aa aa aaa aaaaaaaa. Aa aaaa aaaaaaaaaaa aaaaa, aaaa aaaaa aaaaaaaaaaaaaa aa aaaaaaaaa, aa aaaaa, aa aaaaaa aaa aaaa-aaaaaa. aaa’a aaaa aa aaaa aaa aa—aaaaa aaaaaa aaaa, aa aaa aaaaa. Aaaa aaaaa aa aaaaaaa aaaaaaaa, aaa aa aaa aaaa aaaa aaaa aaaa aaa aaaaaaaaaa aa aaaaaaaa aaaa aaaa aa aa aaa aaaaaaaa. Aaaa aaaaa aa aaaaaaa aaaaaaaa, aaa aa aaa aaaa aaaa aaaa aaaa aaa aaaaaaaaaa aa aaaaaaaa aaaa aaaa aa aa aaa aaaaaaaa. \stopparagraph \stopsection \startsection[title={Section 8 title}] \startparagraph Aaaa aaaaa aa aaaaaaa (aa aaaaaa) aaaaaaaa, aaa aa aaa aaaa aaaa aaaa aaaa aaa aaaaaaaaaa aa aaaaaaaa aaaa aaaa aa aa aaa aaaaaaaa. Aa aaaa aaaaaaaaaaa aaaaa, aaaa aaaaa aaaaaaaaaaaaaa aa aaaaaaaaa, aa aaaaa, aa aaaaaa aaa aaaa-aaaaaa. aaa’a aaaa aa aaaa aaa aa—aaaaa aaaaaa aaaa, aa aaa aaaaa aaaaaaaaaa aaaaaaa. \stopparagraph \stopsection \stopchapter \stoptext -- Rik