# Treated as zero Error while trying to place figure in a column

I am a latex newbie! I just wanted to place a figure in my two column document, I used multicol package but when I want to insert a figure in middle of text I get this Error:

! Missing number, treated as zero.

I used many ways, most of them were sophisticated and I did not figure out what they actually did but none of them were useful. So I ask my question here and hope to get help from you guys! Thanks

by the way, This is part of my code I've problem with:

\documentclass[a4paper]{article}
\usepackage{amsmath}
\usepackage{amsfonts}
\usepackage{wasysym}
\usepackage[labelfont=bf]{caption}
\usepackage[margin={1cm,1cm}]{geometry}
\usepackage{multicol,lipsum,graphicx,float}
\begin{document}
\begin{multicols*}{2}
\begin{figure}[!h]
\centering{\includegraphics[width=7cm]{fig3.png}}
\caption{
this is caption
}
\end{figure}
\end{multicols}
• I don't see the "missing number treated as zero" when I compile your MWE. On the other hand, I do so the warning "Package multicol Warning: Floats and marginpars not allowed inside `multicols' environment!." – user30471 Aug 17 '16 at 1:02
• not central to the question -- \centering does not take an argument. it's essentially a "switch" that is in effect until the end of the current environment, which must end with a paragraph break for the effect to be reliable. (the figure environment by default ends with a paragraph break, but has other problems here, as explained in another comment.) – barbara beeton Aug 17 '16 at 1:31
• I used same picture but a different caption(because previous caption has formulas and I thought maybe that's the problem) but this time the compilation process ends without significant warning except there was no figure in the text. – David Aug 17 '16 at 9:21

As commented by Andrew, multicols does not allow floating environments. As you are trying to force the figure to be exactly at this position with [!h] you may as well just use a center environment instead. To put a caption on this, replace the \caption command by

\captionof{figure}{...}

The \captionof command is defined by the caption package which you are already loading.

\documentclass[a4paper]{article}

\usepackage{amsmath}
\usepackage{amsfonts}
\usepackage{wasysym}
\usepackage[labelfont=bf]{caption}
\usepackage{multicol,lipsum,graphicx,float}

\begin{document}

\begin{multicols*}{2}
\lipsum[1]
\begin{center}
\centering\includegraphics[width=7cm]{example-image-a.png}
\captionof{figure}{this is caption}
\end{center}
\lipsum[2-8]
\end{multicols*}

\end{document}