Hi Hans,
I renounce the Fourier install fonts, but instead, I will use the fonts Utopia.
The following file produces the error :
fab@debian:~$ context ntg44.tex
resolvers | trees | analyzing 'home:texmf'
mtx-context | run 1: luatex --fmt="/home/fab/context/tex/texmf-cache/luatex-cache/context/5fe67e0bfe781ce0dde776fb1556f32e/formats/luatex/cont-en" --jobname="ntg44" --lua="/home/fab/context/tex/texmf-cache/luatex-cache/context/5fe67e0bfe781ce0dde776fb1556f32e/formats/luatex/cont-en.lui" --no-parse-first-line --c:currentrun=1 --c:fulljobname="./ntg44.tex" --c:input="./ntg44.tex" --c:kindofrun=1 --c:maxnofruns=9 "cont-yes.mkiv"
This is LuaTeX, Version beta-0.90.0 (TeX Live 2016)
system commands enabled.
resolvers > trees > analyzing 'home:texmf'
open source > 1 > 1 > /home/fab/context/tex/texmf-context/tex/context/base/mkiv/cont-yes.mkiv
ConTeXt ver: 2016.03.26 13:51 MKIV beta fmt: 2016.4.12 int: english/english
system > 'cont-new.mkiv' loaded
open source > 2 > 2 > /home/fab/context/tex/texmf-context/tex/context/base/mkiv/cont-new.mkiv
close source > 2 > 2 > /home/fab/context/tex/texmf-context/tex/context/base/mkiv/cont-new.mkiv
system > files > jobname 'ntg44', input './ntg44', result 'ntg44'
fonts > latin modern fonts are not preloaded
languages > language 'en' is active
open source > 2 > 3 > /home/fab/ntg44.tex
fonts > typescripts > unknown library 'utopia'
open source > 3 > 4 > /home/fab/context/tex/texmf-context/tex/context/fonts/mkiv/type-imp-texgyre.mkiv
close source > 3 > 4 > /home/fab/context/tex/texmf-context/tex/context/fonts/mkiv/type-imp-texgyre.mkiv
fonts > preloading modern-designsize (mono)
fonts > typescripts > unknown library 'modern-designsize'
fonts > 'fallback modern-designsize tt 12pt' is loaded
open source > 3 > 5 > /home/fab/context/tex/texmf-context/tex/context/sample/common/knuth.tex
close source > 3 > 5 > /home/fab/context/tex/texmf-context/tex/context/sample/common/knuth.tex
tex error > tex error on line 23 in file /home/fab/ntg44.tex: ! Math error: parameter \Umathaxis\textstyle is not set
\stopdisplaymath ...math \Ucheckedstopdisplaymath
\par \ifvmode \ifcase \c_s...
\strc_formulas_stop_formula ...formula \endcsname
\dostoptagged \dostoptagge...
l.23 \stopformula
13 \appendtoks \rm \to \everymathematics
14 \setupmathematics
15 [lcgreek=normal, ucgreek=normal]
16
17 \starttext
18
19 \input knuth
20
21 \startformula
22 {\Bbb P}(x) = \sum_{i=1}^n α_i x^i
23 >> \stopformula
24
25 \stoptext
26
27
28 %%%%%%%
29 %%% Local Variables:
30 %%% Mode: context
31 %%% End:
32
?
################################################
\usetypescriptfile[utopia]
\definetypeface[mainface][rm]
[serif][palatino][default][encoding=texnansi]
\definetypeface[mainface][ss][sans]
[helvetica] [default][encoding=texnansi] [rscale=auto]
\definetypeface[mainface][mm]
[math] [utopia] [default] [rscale=auto]
\setupbodyfont[mainface,12pt]
\appendtoks \rm \to \everymathematics
\setupmathematics
[lcgreek=normal, ucgreek=normal]
\starttext
\input knuth
\startformula
{\Bbb P}(x) = \sum_{i=1}^n α_i x^i
\stopformula
\stoptext
################################################
Thanks,