Wim Neimeijer
6. Dezember 2017 um 22:30
This is the output ConText gives me, when I use a newer version of ConText, 

==== output of run ===
mtx-context     | run 1: luatex --fmt="/opt/context_new/tex/texmf-cache/luatex-cache/context/5fe67e0bfe781ce0dde776fb1556f32e/formats/luatex/cont-en" --jobname="goasy" --lua="/opt/context_new/tex/texmf-cache/luatex-cache/context/5fe67e0bfe781ce0dde776fb1556f32e/formats/luatex/cont-en.lui" --no-parse-first-line --c:currentrun=1 --c:fulljobname="./goasy" --c:input="./goasy" --c:kindofrun=1 --c:maxnofruns=9 "cont-yes.mkiv"
This is LuaTeX, Version 1.06.2 (TeX Live 2018/dev) 
 system commands enabled.
open source     > level 1, order 1, name '/opt/context_new/tex/texmf-context/tex/context/base/mkiv/cont-yes.mkiv'
system          > 
system          > ConTeXt  ver: 2017.11.19 20:15 MKIV beta  fmt: 2017.11.21  int: english/english
system          > 
system          > 'cont-new.mkiv' loaded
open source     > level 2, order 2, name '/opt/context_new/tex/texmf-context/tex/context/base/mkiv/cont-new.mkiv'
close source    > level 2, order 2, name '/opt/context_new/tex/texmf-context/tex/context/base/mkiv/cont-new.mkiv'
system          > files > jobname 'goasy', input './goasy', result 'goasy'
fonts           > latin modern fonts are not preloaded
languages       > language 'en' is active
open source     > level 2, order 3, name '/home/icubic/go/src/bitbucket.org/wneimeijer/goasy/docs/manual/goasy.tex'
fonts           > preloading latin modern fonts (second stage)
fonts           > 'fallback modern-designsize rm 12pt' is loaded
open source     > level 3, order 4, name '/opt/context_new/tex/texmf-context/tex/context/fonts/mkiv/type-imp-libertine.mkiv'
close source    > level 3, order 4, name '/opt/context_new/tex/texmf-context/tex/context/fonts/mkiv/type-imp-libertine.mkiv'
fonts           > typescripts > unknown library 'default'
fonts           > defining > font with asked name 'linlibertiner' is not found using lookup 'file'
fonts           > defining > unknown font 'linlibertiner', loading aborted
fonts           > defining > unable to define 'linlibertiner' as 'libertine-12pt-rm-tf-0--0'
open source     > level 3, order 5, name '../setup_global.tex'
modules         > 'units' is loaded
open source     > level 4, order 6, name '/opt/context_new/tex/texmf-context/tex/context/modules/mkiv/m-units.mkiv'
resolvers       > lua > loading file '/opt/context_new/tex/texmf-context/tex/context/modules/mkiv/x-mathml.lua' succeeded
units           > The units module is obsolete because functionality is built into the core.
close source    > level 4, order 6, name '/opt/context_new/tex/texmf-context/tex/context/modules/mkiv/m-units.mkiv'
open source     > level 4, order 7, name '../setup_colors.tex'
colors          > defining > unknown library 'hex'
colors          > 'rgb' color space is supported
colors          > 'cmyk' color space is supported
open source     > level 5, order 8, name '/opt/context_new/tex/texmf-context/tex/context/base/mkiv/colo-imp-xwi.mkiv'
close source    > level 5, order 8, name '/opt/context_new/tex/texmf-context/tex/context/base/mkiv/colo-imp-xwi.mkiv'
colors          > system 'xwi' is loaded
close source    > level 4, order 8, name '../setup_colors.tex'
open source     > level 4, order 9, name '../setup_language.tex'
close source    > level 4, order 9, name '../setup_language.tex'
open source     > level 4, order 10, name '../setup_title.tex'
close source    > level 4, order 10, name '../setup_title.tex'
open source     > level 4, order 11, name '../setup_i18n.tex'
close source    > level 4, order 11, name '../setup_i18n.tex'
open source     > level 4, order 12, name '../setup_parts.tex'
close source    > level 4, order 12, name '../setup_parts.tex'
open source     > level 4, order 13, name '../setup_chapter.tex'
close source    > level 4, order 13, name '../setup_chapter.tex'
open source     > level 4, order 14, name '../setup_section.tex'
close source    > level 4, order 14, name '../setup_section.tex'
open source     > level 4, order 15, name '../setup_bookmarks.tex'
close source    > level 4, order 15, name '../setup_bookmarks.tex'
open source     > level 4, order 16, name '../setup_toc_foc.tex'
close source    > level 4, order 16, name '../setup_toc_foc.tex'
open source     > level 4, order 17, name '../setup_definitions.tex'
close source    > level 4, order 17, name '../setup_definitions.tex'
open source     > level 4, order 18, name '../setup_hyphen_rules.tex'
close source    > level 4, order 18, name '../setup_hyphen_rules.tex'
open source     > level 4, order 19, name '../setup_matrix.tex'
close source    > level 4, order 19, name '../setup_matrix.tex'
open source     > level 4, order 20, name '../setup_code.tex'
close source    > level 4, order 20, name '../setup_code.tex'
close source    > level 3, order 20, name '../setup_global.tex'
open source     > level 3, order 21, name '../setup_frontmatter.tex'
structures      > begin of sectionblock 'frontpart'
open source     > level 4, order 22, name 'title.tex'
metapost        > initializing instance 'metafun' using format 'metafun'
metapost        > loading 'metafun' as '/opt/context_new/tex/texmf-context/metapost/context/base/mpiv/metafun.mpiv' using method 'default'
metapost        > initializing number mode 'scaled'
backend         > xmp > using file '/opt/context_new/tex/texmf-context/tex/context/base/mkiv/lpdf-pdx.xml'
pages           > flushing realpage 1, userpage 1, subpage 1
open source     > level 5, order 23, name '../setup_copyright.tex'
close source    > level 5, order 23, name '../setup_copyright.tex'
pages           > flushing realpage 2, userpage 1
close source    > level 4, order 23, name 'title.tex'
structure       > sectioning > title @ level 2 : 0.0 -> \headtext {content}
fonts           > defining > font with asked name 'linlibertinerb' is not found using lookup 'file'
fonts           > defining > unknown font 'linlibertinerb', loading aborted
fonts           > defining > unable to define 'linlibertinerb' as 'libertine-12pt-rm-bf-0-c-0'

tex error       > tex error on line 418 in file ../setup_frontmatter.tex: ! Undefined control sequence


\14>:texta ...idth=\textwidth ]{ {\cornflowerblue 
                                                  \userpagenumber } \hfill }
\17>>1 #1,->\syst_setups {#1}
                             \syst_helpers_do_process_comma_item 
\syst_helpers_do_process_comma_list ...rgument #1,
                                                  ]\relax \global \advance \...
<argument> \ignorecrlf \setups {texta}
                           {}{}{}
\secondoftwoarguments #1#2->#2
                              
\page_layouts_process_element_single_indeed ...#4}
                                                  \fi \endgroup 
...
l.39 \completecontent[partnumber=no]

You’re using the command \cornflowerbluein in your setups (probably for the header or footer)
to change the color of the page number but ConTeXt doesn’t create individual commands
anymore for colors which are loaded from the color files.


You can fix fix when you change the color setting to

    \color[cornflowerbluein]{\userpagenumber}

or even better you set the color with

    \setupheader[color=cornflowerbluein]


Wolfgang