Dear all, I didn’t test “\startcolumnset … \stopcolumnset” for some time, because I got error whenever I tested it under Mac OS Big Sur. However, two days ago, I tested it, and found that it was working. I install updated version today and run a test file again. Finally, I get an output without error! I don't know what is happened, but it is a good news. Here is a sample file which I simplified one that is given by one of the experts. Someone may modify it better. Thanks to ConTeXt team. Best regards, Dalyoung \startuseMPgraphic{squareBox} draw topboundary OverlayBox leftenlarged 1mm rightenlarged 1mm; draw bottomboundary OverlayBox leftenlarged 1mm rightenlarged 1mm; draw rightboundary OverlayBox shifted (1mm,0); draw leftboundary OverlayBox shifted (-1mm,0); \stopuseMPgraphic \defineoverlay [headerBox] [\useMPgraphic{squareBox}] \startuseMPgraphic{verticalrule3} draw rightboundary OverlayBox shifted (1mm,0); %if CurrentColumn = 1: shifted(-2mm,0) fi ; draw leftboundary OverlayBox shifted (-1mm,0); %if CurrentColumn = 2: shifted(2mm,0) fi ; draw bottomboundary OverlayBox leftenlarged 1mm rightenlarged 1mm; \stopuseMPgraphic \defineoverlay [verticalrule] [\useMPgraphic{verticalrule3}] \definecolumnset [exam] [n=2, background=verticalrule] \setuplayout[width=19cm, height=26cm, header=1cm, footer=.5cm,backspace=1cm] \setupheader[before=\vfil, after=\vfil] \setupbackgrounds[header][text][frame=off, background=headerBox, align=lohi]%topframe= \setupbackgrounds[footer][text][frame=off, background=screen] \define[3]\headTitle{\setupheadertexts[][\bf #1 \hfill #2 \hfill #3 \hfill ID: \hskip 2cm Name: \hskip 2cm]} \setupmathematics[autopunctuation=no, integral=nolimits] \setupbodyfont[rm,10pt] \setuppagenumbering[location=footer] \setupcolors[state=start] %\setupexternalfigure[directory={/Users/graph/Documents/figures,}] \headTitle{2021. 12. 12.}{Set Theory}{Final Exam} \starttext \startcolumnset[exam] \startitemize[n] \item The first problem. \column \item The second problem. \column \item The third problem. \column \item The third problem. \stopitemize \stopcolumnset \stoptext