Hi Hans, I get this error running 2013.08.14 15:25: ! LuaTeX error .../context/tex/texmf-context/tex/context/base/font-col.lua:180: table index is nil stack traceback: .../context/tex/texmf-context/tex/context/base/font-col.lua:180: in function 'fontcollectionclone' [string "\directlua "]:1: in main chunk. system > tex > error on line 137 in file /Users/tas/context/tex/texmf-context/tex/context/base/cont-yes.mkiv: LuaTeX error ... \ctxcommand #1^^@-\directlua {commands.#1} l.137 } \ctxcommand #1^^@-\directlua {commands.#1} \font_fallbacks_prepare_indeed ...backs_prepare #1 \endgroup <inserted text> ...llbacks_prepare_indeed \m_font_class_fallbacks \fi \else \font_fallbacks_... \font_helpers_low_level_define ...everydefinefont \c_font_feature_inheritanc... ... l.91 \stopluacode Unfortunately, I have no idea what triggers it, same document compiles fine with a July beta. All best Thomas