I had some testfiles gathered, for example the following does work: % engine=luatex \starttext \startlua a = 1.5 b = 1.8 c = a*b tex.print(c) \stoplua \stoptext But this one gives an error, see the output below. It seems the \startlue...\stoplua is the culprit, because comment them out and the error disappears. What is going on? % engine=luatex \starttext \startlua \definefontfeature[smallcaps][language=DFLT,script=latn,smcp=yes] \font\palasmallcaps=texgyrepagella-regular*smallcaps \palasmallcaps This is a text in small capitals. \stoplua \stoptext 108 ~/Temp/luatex: luatex luatest3.tex TeXExec | processing document 'luatest3.tex' TeXExec | no ctx file found TeXExec | tex processing method: context TeXExec | TeX run 1 TeXExec | writing option file luatest3.top TeXExec | using randomseed 1317 TeXExec | tex engine: luatex TeXExec | tex format: cont-en (./luatest3.tex ConTeXt ver: 2008.01.28 21:28 MKIV fmt: 2008.2.15 int: english/ english language : language en is active system : cont-new loaded (/usr/local/texlive/texmf-context/tex/context/base/cont-new.tex systems : beware: some patches loaded from cont-new.tex (/usr/local/texlive/texmf-context/tex/context/base/cont-new.mkiv lua : used config path - /usr/local/texlive/2007/texmf/ web2c/texmf.cnf lua : used cache path - //usr/local/texlive/texmf-context/ cache/luatex-cache/context/5b25423ad16f5b11dc34abcf44e70ed1 ) (/usr/local/texlive/texmf-context/tex/context/base/cont-mtx.tex)) system : cont-old loaded (/usr/local/texlive/texmf-context/tex/context/base/cont-old.tex loading : Context Old Macros ) system : cont-fil loaded (/usr/local/texlive/texmf-context/tex/context/base/cont-fil.tex loading : Context File Synonyms ) system : cont-sys.rme loaded (/usr/local/texlive/texmf-context/tex/context/user/cont-sys.rme (/usr/ local/texlive/texmf-context/tex/context/base/type-tmf.tex) (/usr/local/ texlive/texmf-context/tex/context/base/type-siz.tex) (/usr/local/ texlive/texmf-context/tex/context/base/type-otf.tex)) bodyfont : 12pt rm is loaded specials : tex,postscript,rokicki loaded system : luatest3.top loaded (./luatest3.top specials : loading definition file tpd (/usr/local/texlive/texmf-context/tex/context/base/spec-tpd.tex specials : loading definition file fdf (/usr/local/texlive/texmf-context/tex/context/base/spec-fdf.tex (/usr/ local/texlive/texmf-context/tex/context/base/spec-fdf.mkiv)) specials : fdf loaded ) specials : fdf,tpd loaded ) (./luatest3.tuo) (./luatest3.tuo) systems : begin file luatest3 at line 2 ! Use of \dodoincrement doesn't match its definition. \doifnextcharelse ...tertoken =#1\def \!!stringa { #2}\def \!!stringb {#3}\fu... \definefontfeature zerocount { [smallcaps] [language=DFLT,... \expanded ...\long \xdef \@@expanded {\noexpand #1 }\@@expanded l.7 \stoplua ? And this one is even worse, giving an: ! TeX capacity exceeded, sorry [parameter stack size=6000]. \doappendtoks #1\to #2-> \def \@@toks {#2}\@@scratchtoks \@EA {\gobbleoneargu... \doappendtoks ...htoks \@EA {\gobbleoneargument #1 }\dodoappendtoks \doappendtoks ...htoks \@EA {\gobbleoneargument #1 }\dodoappendtoks \doappendtoks ...htoks \@EA {\gobbleoneargument #1 }\dodoappendtoks \doappendtoks ...htoks \@EA {\gobbleoneargument #1 }\dodoappendtoks \doappendtoks ...htoks \@EA {\gobbleoneargument #1 }\dodoappendtoks ... l.35 \stoplua % engine=luatex \startlua \starttypescript [sans] [franklin] \definefontsynonym [FranklinBookRegular] [name:FranklinGothicBookITC-Regular] [features=default] \definefontsynonym [FranklinMediumRegular] [name:FranklinGothicMediumITC-Regular] [features=default] \definefontsynonym [FranklinDemiRegular] [name:FranklinGothicDemiITC-Regular] [features=default] \definefontsynonym [FranklinHeavyRegular] [name:FranklinGothicHeavyITC-Regular] [features=default] \definefontsynonym [FranklinBookItalic] [name:FranklinGothicBookITC-Italic] [features=default] \definefontsynonym [FranklinDemiItalic] [name:FranklinGothicMediumITC-Italic] [features=default] \definefontsynonym [FranklinHeavyItalic] [name:FranklinGothicDemiITC-Italic] [features=default] \definefontsynonym [FranklinMediumItalic] [name:FranklinGothicHeavyITC-Italic] [features=default] \stoptypescript \starttypescript [sans] [franklin] \definefontsynonym [Sans] [FranklinBookRegular] [features=default] \definefontsynonym [SansItalic] [FranklinBookItalic] [features=default] \definefontsynonym [SansBold] [FranklinDemiRegular] [features=default] \definefontsynonym [SansBoldItalic] [FranklinDemiItalic] [features=default] \definefontsynonym [SansSlanted] [SansItalic] [features=default] \definefontsynonym [SansBoldSlanted] [SansBoldItalic] [features=default] \definefontsynonym [SansCaps] [Sans] [features=smallcaps] \stoptypescript \definetypeface[franklin][rm][sans][franklin][default] \definetypeface[franklin][ss][sans][franklin][default] \definetypeface[franklin][tt][mono][modern] [default][rscale=1.12] \definetypeface[franklin][mm][math][iwona] [default][rscale=1.02] \setupbodyfont[franklin,ss,10pt] \stoplua Hans van der Meer