# Pdflatex does not compile Beamer class documents

For several years now I use the Beamer class to create slides with Latex. For whatever reason pdflatex does not compile my Latex documents anymore. It stops with the following error message:

```! Undefined control sequence. \Gm@lmargin ->\Geom@lmargin ```

I found out that this seems to be caused by an update of the geometry package. The newer version breaks the Beamer class. The workaround is to insert the following code before the document class definion:

```\makeatletter\let\ifGm@compatii\relax\makeatother ```

Actually, I found this solution in the following posting. I think it may help several other people, hence, I concluded it here again.