Dear ConTeXt folks, having upgraded ConTeXt ver: 2011.10.14 22:47 MKIV fmt: 2011.10.15 int: english/english. to ConTeXt ver: 2011.11.23 18:58 MKIV fmt: 2011.11.24 int: english/english With \starttext \placeformula \startformula A^\prime \stopformula \stoptext I get the following error. fonts > fallback modern rm 12pt is loaded ! Missing { inserted. system > tex > error on line 4 in file exponent-regression.tex: Missing { inserted ... 1 \starttext 2 \placeformula 3 \startformula 4 >> A^\prime 5 \stopformula 6 \stoptext 7 <to be read again> ^ \prime ...char \textfont \zerocount "FE325\relax ^ \bgroup \expandafter \dodo... l.4 A^\prime ? As a workaround `A^{\prime}` can be used. Thanks, Paul