Sorry, I don't have a minimal example yet, but processing some of my xml files dies with this error: ! Math error: parameter \Umathquad\crampedscriptscriptstyle is not set. \XML:ent:approx ->$\approx $ l.2 ≈ \xmlflush #1->\ctxlua {lxml.flush("#1")} \@@su:xml:content #1->\xmlflush {#1} \par l.1 \xmlsetup{292}{xml:content} \xmlfirst #1#2->\ctxlua {lxml.first("#1","#2")} ... or ! Math error: parameter \Umathquad\crampedscriptscriptstyle is not set. \mathematics #1->\relax \ifmmode #1\else $#1$ \fi \XML:ent:lt ...ies \string <\else \mathematics {<} \fi l.5 < \xmlflush #1->\ctxlua {lxml.flush("#1")} \@@su:xml:content #1->\xmlflush {#1} \par l.1 \xmlsetup{880}{xml:content} I haven't succeeded in narrowing down the error, but what does \Umathquad and \crampedscriptscriptstyle mean? I couldn't find it in the source. Thomas