Hi, I'm in the process of updating to TeXlive 2023 after a long time of light use with 2018. One issue I'm now having is an error when I try to use Neo Euler as my math font. \definefontfamily[mypalatinoeuler][rm][TeX Gyre Pagella] \definefontfamily[mypalatinoeuler][mm][Neo Euler] \setupbodyfont[mypalatinoeuler] \starttext $x=1$ \stoptext Result: mathematics > tweak > 'Neo-Euler', size 7, math size 3, version 'Version 000.002' found, version 'Version 000.002 ' expected tex error > tex error on line 5 in file ./euler_problem.tex: lua error: registered function call [1160]: ...xlive/2023/texmf-dist/tex/context/base/mkxl/math-act.lmt:3254: stack overflow stack traceback: ...xlive/2023/texmf-dist/tex/context/base/mkxl/math-act.lmt:3254: in upvalue 'add' ...xlive/2023/texmf-dist/tex/context/base/mkxl/math-act.lmt:3254: in upvalue 'add' ...xlive/2023/texmf-dist/tex/context/base/mkxl/math-act.lmt:3254: in upvalue 'add' ...xlive/2023/texmf-dist/tex/context/base/mkxl/math-act.lmt:3254: in upvalue 'add' ...xlive/2023/texmf-dist/tex/context/base/mkxl/math-act.lmt:3254: in upvalue 'add' ...xlive/2023/texmf-dist/tex/context/base/mkxl/math-act.lmt:3254: in upvalue 'add' ...xlive/2023/texmf-dist/tex/context/base/mkxl/math-act.lmt:3254: in upvalue 'add' ...xlive/2023/texmf-dist/tex/context/base/mkxl/math-act.lmt:3254: in upvalue 'add' ...xlive/2023/texmf-dist/tex/context/base/mkxl/math-act.lmt:3254: in upvalue 'add' ...xlive/2023/texmf-dist/tex/context/base/mkxl/math-act.lmt:3254: in upvalue 'add' ... (skipping 99970 levels) ...xlive/2023/texmf-dist/tex/context/base/mkxl/math-act.lmt:3267: in local 'action' ...xlive/2023/texmf-dist/tex/context/base/mkxl/math-act.lmt:3617: in upvalue 'tweaklist' ...xlive/2023/texmf-dist/tex/context/base/mkxl/math-act.lmt:3653: in upvalue 'applytweaks' ...xlive/2023/texmf-dist/tex/context/base/mkxl/math-act.lmt:3682: in upvalue 'mathematics_tweakaftercopyingfont' [string "local mathematics_tweakaftercopyingfont = mat..."]:5: in local 'runner' ...xlive/2023/texmf-dist/tex/context/base/mkxl/font-ctx.lmt:510: in field 'aftercopyingcharacters' ...xlive/2023/texmf-dist/tex/context/base/mkxl/font-con.lmt:859: in field 'scale' ...xlive/2023/texmf-dist/tex/context/base/mkxl/font-otl.lmt:659: in function <...xlive/2023/texmf-dist/tex/context/base/mkxl/font-otl.lmt:651> (...tail calls...) ...xlive/2023/texmf-dist/tex/context/base/mkxl/font-def.lmt:378: in function <...xlive/2023/texmf-dist/tex/context/base/mkxl/font-def.lmt:366> (...tail calls...) ...xlive/2023/texmf-dist/tex/context/base/mkxl/font-def.lmt:485: in field 'read' ...xlive/2023/texmf-dist/tex/context/base/mkxl/font-ctx.lmt:1377: in function <...xlive/2023/texmf-dist/tex/context/base/mkxl/font-ctx.lmt:1234> (...tail calls...) It works if I use, say, [TeX Gyre Pagella Math] in place of [Neo Euler]. 15:49:15 $ context --version mtx-context | ConTeXt Process Management 1.04 mtx-context | mtx-context | main context file: /usr/local/texlive/2023/texmf-dist/tex/context/base/mkiv/context.mkiv mtx-context | current version: 2023.03.10 12:15 mtx-context | main context file: /usr/local/texlive/2023/texmf-dist/tex/context/base/mkxl/context.mkxl mtx-context | current version: 2023.03.10 12:15 I don't know how to diagnose any further. Cheers, Rory Molinari