With  ConTeXt  ver: 2021.04.28 18:39 LMTX  fmt: 2021.4.29  int, I am now
getting the following error on compiling with files that were OK
previously. Is there something that I need to change?

Alan

lua error       > lua error on line 232 in file ../../env_Aestimatio-00.tex:

registered function call [1151]:
...TeX/tex/texmf-context/tex/context/base/mkiv/font-sel.lua:648: attempt to
index a nil value (field 'tf')
stack traceback:
...TeX/tex/texmf-context/tex/context/base/mkiv/font-sel.lua:648: in field
'filefallback'
...TeX/tex/texmf-context/tex/context/base/mkiv/font-sel.lua:666: in field
'mathfallback'
...TeX/tex/texmf-context/tex/context/base/mkiv/font-sel.lua:692: in field
'fallback'
...TeX/tex/texmf-context/tex/context/base/mkiv/font-sel.lua:782: in
function <...TeX/tex/texmf-context/tex/context/base/mkiv/font-sel.lua:777>
(...tail calls...)

222     expansion=quality,
223     mode=node,
224     force=yes,
225     ]
226     \definefallbackfamily[mainface] [mm] [STIX Two Text]
227         [range=digitsnormal,
228     force=yes,
229     features=f:oldstyle]
230
231     \definefontfamily[mainface][mm][STIX Two Math]
232 >>
233     \setupbodyfont[mainface, 10pt]
234
235     \setupalign[hanging, stretch, hz]
236
237     %%%%%%%%%% French
238     %At beginning insert:
239     % \mainlanguage[fr]
240     % \setcharacterspacing[frenchpunctuation]
241     % \startsetups[footnote:french]
242     %\setcharacterspacing[frenchpunctuation]

mtx-context     | fatal error: return code: 256