# Firefox PDF viewer vs beamer + pgfpages

Consider the following MWE to be previewed in the build in PDF previewer in Firefox

\documentclass[handout]{beamer}
\usepackage{pgfpages}
\pgfpagesuselayout{8 on 1}[a4paper,border shrink=4mm]
\begin{document}
\begin{frame}
$\bigcup_n \sum_n$
$\underbrace{aaaaaa}_{bbb}$
\end{frame}
\end{document}


Obervations: First of this is what I see in my FF.

Notice how the \bigcup and \sum are wrong.

Further observations:

1. If the \underbrace is removed, things are ok
2. if the \pgfpagesuselayout line is removed, everything renders ok.

The same file rendered in Chrome, displays just fine.

Is this some kind of artefact in FF?

• It is an artifact of PDF.js. Request to preview in reader or open with reader outside firefox. – percusse Sep 1 '15 at 12:27
• @percusse You can do it, but if the readers of your document won't, then it's bad :-( – yo' Sep 1 '15 at 12:33
• @yo' Save one world at a time ;) They have a GitHub page for bug reports etc. – percusse Sep 1 '15 at 12:42

• @daleif: David has a time machine. :) – Paulo Cereda Sep 1 '15 at 13:42
• @daleif: if I recall correctly, there's nightly, then aurora, then stable. David lives on the wibbly wobbly timey wimey Firefoxy edge thingy. :) – Paulo Cereda Sep 1 '15 at 14:15