Including signature images kills scrlttr2

Question

I'm really weirded out. The following letter compiles nicely:

\documentclass{scrlttr2}
\usepackage[T1]{fontenc}
\usepackage[utf8]{inputenc}
\usepackage{ngerman}
\usepackage[a4paper, textwidth=490pt, textheight = 690pt]{geometry}
\setkomavar{signature}{John Doe}
\begin{document} 
\begin{letter}{Dr X \\ Evil Corp}
\setkomavar{subject}{Application}
\opening{Dear Dr X,}
blabla
\closing{Kind regards,}
\end{letter} 
\end{document}

---

But when I include an (existing) signature image by replacing

\setkomavar{signature}{John Doe}

with

\setkomavar{signature}{\includegraphics{sig} \\\\ John Doe},

my compiler refuses to create a pdf, saying

Undefined control sequence \closing{Kind regards,}

I don't know what to do.

Answer 1

The error is actually

! Undefined control sequence.
\scr@signature@var ->\includegraphics 
                                      {sig}John Doe
l.12 \closing{Kind regards,}

When you get a Undefined control sequence error, the macro (control sequence) it complains about is the last one on the first line, in this case \includegraphics.

\includegraphics is defined by the graphicx package, which should always be added if you're adding images. Hence, adding

\usepackage{graphicx}

will solve it.