How do you put multiple paragraphs in a caption?

Question

I have a really long caption for a figure in a LaTeX document. I would like to break the caption into a few paragraphs. How do I do that?

As per the request below, I removed everything I could while still getting the errors I mentioned in my comment. The resulting file is this:

\documentclass{article}

\usepackage[pdftex]{graphicx}
\usepackage{hyperref}

\graphicspath{{./Figures/}}

\begin{document}

\begin{figure}
\includegraphics{NodesEdgesExample2.pdf}
\caption{
Paragraph 1.  

Paragraph 2.

Paragraph 3.
}
\label{fig:AltNavigationConcept}
\end{figure}

\end{document}

We're building it in TeXnicCenter, and I verified that another person in my research lab also gets the same errors on his computer with the above code.

Answer 1

The following quote from the manual of the caption package (p. 12) is also true for the LaTeX standard definition of \caption:

If your caption contains more than one paragraph, you have to specify an alternative caption for the list-of-figures using the optional argument of \caption or \captionof, otherwise you will get an error message.

EDIT: To clarify: A multi-paragraph figure caption without a single-paragraph optional variant will produce an error even if you don't use \listoffigures in your document.

\documentclass{article}

\begin{document}

\listoffigures

\section{foo}

\begin{figure}[!ht]
\centering
\rule{1cm}{1cm}
\caption[LoF entry]{The first paragraph of a figure's caption.

And the second.}
\end{figure}

\end{document}

Answer 2

You can use caption package.

\documentclass{article}
\usepackage[demo]{graphicx}
\usepackage{caption}
\usepackage{lipsum}
\begin{document}
\captionsetup{margin={15pt},parskip=10pt,format=hang,indention=-.8cm}
\begin{figure}[h]
\centering
\includegraphics[width=\textwidth]{myfigure}
\caption[my caption]{\lipsum[1-2]}
\end{figure}
This is regular text. \lipsum[1]
\end{document}

Note: If your caption contains at least two paragraphs, then you should add a short title [my caption] in \caption[my caption]{\lipsum[1-2]}for LOF. Otherwise it will give an error.