Hi Hans, A file which used to be typeset correctly with the previous versions of lmtx, now produces an error. Despite the error message being extremely cryptic: Error ! Missing number, treated as zero I could guess the origin of the bug, which seems to be \wordright, but although the following minimal example shows a bug it does not produce the same ERROR output page: %%%% the square ''end of proof'' \definesymbol[Fin][\mathematics{\square}] \def\qed{\wordright{\symbol[Fin]}} \starttext \startformula a^2 + b^2 = c^2 \stopformula \qed % the problem is here \stoptext In the above example if one adds something before \qed, then the square end-of-proof appears. However in my real file ConTeXt ouputs an error page and says: Error ! Missing number, treated as zero. Best regards: Otared