Hi Will, (please keep Cc, thanks!)
Norbert here. Downstream at Debian, but it is the same in upstream TeX Live, I got a bug report that the latest version of unicode-math does not work properly with xelatex. The following minimal working example breaks under xelatex: \documentclass{article} \usepackage{unicode-math} \begin{document} $\widetilde{\mathbf{a}}$ \end{document} With the following error: Error message: ! Internal error: bad native font flag in `map_char_to_glyph' Do you have an idea what might have triggered this? All the best Norbert -- PREINING Norbert http://www.preining.info Accelia Inc. + JAIST + TeX Live + Debian Developer GPG: 0x860CDC13 fp: F7D8 A928 26E3 16A1 9FA0 ACF0 6CAC A448 860C DC13