[Tex/LaTex] Implementation of caption below figure does not work at all, error

captionserrorsfloats

after you previously helped me this very afternoon I have an other unsolved question and my internet research doesn't lead to anything.

I want to include a simple figure (.png file) in my document, but as soon as I want to caption it, it will not compile and produces an error message (included below)

First, let me give you my preamble:

\documentclass[a4paper,11pt]{memoir}

% packages
\usepackage{kantlipsum}
\usepackage[utf8]{inputenc}
\usepackage[T1]{fontenc}
\usepackage{csquotes}
% Language
\usepackage[english]{babel}
%\usepackage[ngerman]{babel}
\usepackage{helvet}
\usepackage[style=numeric-comp, backend=bibtex, sorting=none]{biblatex}
\usepackage{graphicx}
\usepackage{color} % \definecolor{heatred}[RGB}{170,0,0}
\usepackage{amsmath}
\usepackage{amsfonts}
\usepackage{color}
\usepackage{siunitx} % \SI{15e3}{\kg}, \SI{0.2}{\m\per\s}, \si{\kWh}
\usepackage{mdwlist} % compact lists: \begin{enumerate*}, \begin{itemize*}
\usepackage{hyperref}
\usepackage{bm} % bold italic symbols in math mode
\usepackage{eurosym}
\usepackage{pdfpages}
\usepackage{tikz}

This is the code, where the figure is implemented in the text:

\begin{figure}[hb]
\centering
\includegraphics[width=\textwidth]{img/setup.png}
\caption{basic components of ABC}
\label{fig:setup}
\end{figure}

This is the ouput I receive, when the caption is not commented:

.98 \cleardoublepage
                      [2] (tex/00-statement-en.tex) [3] [4] (thesis.toc)
[5] (tex/01-introduction.tex [6]
Underfull \vbox (badness 6078) has occurred while \output is active [7])
(tex/02-structure-and-characteristics-of-mwt.tex [8]

LaTeX Warning: Reference `fig:setup' on page 9 undefined on input line 11.


Underfull \hbox (badness 10000) in paragraph at lines 9--16

<img/setup.png, id=90, 480.85158pt x 172.13918pt> <use img/setup.png>
! Undefined control sequence.
\@contdelim ->:

l.20 \caption{basic components of ABC}

? 

When commenting \caption… the picture is included, but there is no reference below it (i.e. Figure 2).

An other strange thing is the following:
Since the figure is labeled, I want to refer to it in the text written on the same site. Example: In Fig. \ref{fig:setup} something is shown. at the position where I want to indicate the picture. There are no(!) other labels of figures before in this chapter. However the output of the mentioned command results in this: In Fig. 2 something is shown, so the label count starts with number 2 (???, I have no idea …). Linked to this phenomenon is the situation, that if i include more labels on the very same site (and chapter and so on), the output number (so the number which is show when using \ref{XYZ}) does not change. ALL "labels" are referred as "2". I hope my explanation is detailed enough, if not please comment and I will do my very best to clarify it. Thank you very much!

Best Answer

The answer is as simple as it gets. I trusted in a complete preamble, but the \usepackage{caption} was somehow missing. Thank you again for your help and time! I appreciate it!