Hello,
I want to create a template with a header on the first page for student testing. If the document contains text that is on more than one page, it works perfectly. On the other hand, if the document has text on one page, it does not work.

Thanks.

Fabrice

\setuppagenumbering[alternative=,location=]
 
  \showframe
 
  \definelayout
    [firstpage]
    [topspace=10mm,
     header=10mm,
     footer=10mm,
     height=middle,
     backspace=20mm,
     width=middle]

  \definelayout
    [first]
    [firstpage]
     
  \setuplayout
   [topspace=10mm,
    header=\zeropoint,
    footer=10mm,
    height=middle,
    backspace=20mm,
    width=middle]

  \setupbackgrounds
   [header]
   [text]
   [frame=off,
    topframe=on,
    bottomframe=on,
    framecolor=red,
    rulethickness=1pt]

  \setupheadertexts
    [First page]

  \starttext
  \dorecurse{8}{\input knuth}  % ok

%  \dorecurse{8}{\input knuth}  no ok
  \stoptext