This beamer attempt produces the error "Too many math alphabets used in version normal.". Using the article class produces no error as does removing either chemmacros or siunitx, but I need those packages.
\documentclass{beamer}
\usepackage{chemmacros}
\chemsetup{greek=fourier}
\usepackage{siunitx}
\usepackage{helvet, mathpazo}%suggested by siunitx
\begin{document}
\begin{frame}
\num{1+2i}
\end{frame}
\end{document}

siunitxdocumentation suggests. Removing the\usepackage{helvet, mathpazo}line throws a single error, while keeping it throws two.At this point I'm considering to give up on pdfLaTeX and use XeLaTeX.
– Kurzd Mar 30 '16 at 20:18