Using beamer with wuerzburg outer and chamfered inner theme I created a long presentation with 100+ slides. After 9 slides the frame numbers are not correctly aligned, the total framenumber is visible but the current framenumber is above it, and I did not find a way to correctly align it.
In the MWE on the last 30 frames tried the solution here: Add Footer Text to All Slides in Beamer but this one removes the original footline background (colortheme).
If you uncomment the \usecolortheme{shark}
it is more visible why the current framenumber disappears.
\documentclass{beamer}
\mode<beamer>{
\useoutertheme[glossy]{wuerzburg}
\useinnertheme[shadow,outline]{chamfered}
\usecolortheme{shark}
}
\setbeamertemplate{navigation symbols}{}
\usepackage{blindtext}
\begin{document}
\begin{frame}[allowframebreaks]{Original footline}
\blindtext[100]
\end{frame}
\setbeamertemplate{footline}[text line]{%
\parbox{\linewidth}{\vspace*{-8pt}some text\hfill\insertframenumber/\inserttotalframenumber}
}
\begin{frame}[allowframebreaks]{Different footline}
\blindtext[50]
\end{frame}
\end{document}