Hi, todays beta gives an error with this test (taken from strc-reg.kmiv at line 35): \starttext \placeregister[index] test \index{aa} test \startregister[index][x]{bb} test \page test \page test \page test \stopregister[index][x] \stoptext ! LuaTeX error ...text/tex/texmf-context/tex/context/base/sort-ini.lua:106: attempt to compare nil with number stack traceback: ...text/tex/texmf-context/tex/context/base/sort-ini.lua:106: in function <...text/tex/texmf-context/tex/context/base/sort-ini.lua:105> ...text/tex/texmf-context/tex/context/base/sort-ini.lua:416: in function 'firstofsplit' ...text/tex/texmf-context/tex/context/base/strc-reg.lua:403: in function 'finalize' ...text/tex/texmf-context/tex/context/base/strc-reg.lua:427: in function 'analyzed' ...text/tex/texmf-context/tex/context/base/strc-reg.lua:789: in function 'process' <main ctx instance>:1: in main chunk. system > error on line 8 in file index_ff.tex: LuaTeX error ... Greetings, Steffen BTW: I found three invalid characters (form feed?) in strc-reg.mkiv: at line 549, 568, 632.