How do I correct an Undefined Control Sequence when using includegraphics?

Question

I understand this my concern has been expressed previously here,`here2 and here3 but the responses cannot still solve my problem.

I included an image in my Latex code, which was running normally until today. All attempts only show undefined control sequence.\includegraphics{IDP}. I have checked for errors, retyped the code without any luck. It seems there is something I am not doing right.

I would very much appreciate any assistance on how to correct my code.

Here is the code I am using

\documentclass[12pt,a4paper]{memoir}
\usepackage[utf8]{inputenc}
\usepackage[T1]{fontenc}
\usepackage[american]{babel}
\usepackage[strict]{csquotes}
\usepackage{apacite}
\usepackage{amsmath}
\usepackage{amsfonts}
\usepackage{amssymb}
\usepackage{makeidx}
\usepackage{graphicx}
\graphicspath{ {./images/} }
\begin{document}

\begin{figure}[htp]
\includegraphics{IDP}
\caption*{Source:~\citeA{dunning1996investment}}
\caption{Patterns of Investment Development}
\label{figIDP}
\end{figure}


\end{document}