Hello there. See the following minimal example. Without the \setupinteraction the document compiles just fine. %% begin \setupinteraction[state=start] \starttext hello \startcomment This won’t be published \stopcomment \stoptext %% end Best regards. Error log: mtx-context | run 1: luatex --fmt="/media/data/melmoth/progetti/context-cutting-edge/tex/texmf-cache/luatex-cache/context/2448223e6631addb83df348d74153606/formats/cont-en" --lua="/media/data/melmoth/progetti/context-cutting-edge/tex/texmf-cache/luatex-cache/context/2448223e6631addb83df348d74153606/formats/cont-en.lui" --backend="pdf" "./min.tex" \stoptext This is LuaTeX, Version beta-0.70.1-2011051923 (rev 4277) \write18 enabled. (min.tex ConTeXt ver: 2012.01.25 14:16 MKIV fmt: 2012.2.1 int: english/english system > cont-new.mkiv loaded (/media/data/melmoth/progetti/context-cutting-edge/tex/texmf-context/tex/context/base/cont-new.mkiv system > beware: some patches loaded from cont-new.mkiv ) system > min.top loaded (min.top) fonts > latin modern fonts are not preloaded languages > language en is active {/media/data/melmoth/progetti/context-cutting-edge/tex/texmf-context/fonts/map/pdftex/context/mkiv-base.map} fonts > preloading latin modern fonts (second stage) fonts > typescripts > unknown: library 'loc' {/media/data/melmoth/progetti/context-cutting-edge/tex/texmf/fonts/map/dvips/lm/lm-math.map}{/media/data/melmoth/progetti/context-cutting-edge/tex/texmf/fonts/map/dvips/lm/lm-rm.map} fonts > fallback modern rm 12pt is loaded check > missing or ungrouped '=' after 'comment' in line 10 (182>comment:) ! LuaTeX error ...edge/tex/texmf-context/tex/context/base/scrn-wid.lua:120: incorrect index value -1 for tex.setbox() stack traceback: [C]: ? ...edge/tex/texmf-context/tex/context/base/scrn-wid.lua:120: in function 'insertcomment' <main ctx instance>:1: in main chunk. system > tex > error on line 13 in file min.tex: LuaTeX error ... 3 \setupinteraction[state=start] 4 5 \starttext 6 7 hello 8 9 \startcomment 10 11 This won’t be published 12 13 >> \stopcomment 14 15 \stoptext 16 \ctxcommand ...\directlua \zerocount {commands.#1} \184>normal ...\commentparameter \c!textlayer " }} \wd \b_scrn_comment_link \... \scrn_comment_stop ->\scrn_comment_inject \egroup l.13 \stopcomment ? X -- Marco