Hello,
I compiled this file with a strange exit for mathematical formula.
What's missing in my file ?
Thank you.
Fabrice

\loadtypescriptfile[mathdesign] 
\usetypescriptfile[utopia]

\definetypeface[mainface][rm]
               [serif][palatino][default][encoding=texnansi]
\definetypeface[mainface][ss][sans]
               [helvetica] [default][encoding=texnansi] [rscale=auto]
\definetypeface[mainface][mm]
               [math] [utopia] [default] [rscale=auto]

\setupbodyfont[mainface,12pt]


\starttext

\input knuth

\startformula
   f(x) = \sum_{i=1}^n a_i x^i
\stopformula

\stoptext