Using figures in subfiles

Question

I have just started to use the subfilespackage. I have the following folder structure:

|-Document
    | Test.tex
    |-img
       | hierarchy.png
    |-tex
       | subtest.tex   

The code for each document goes:

For Test.tex:

\documentclass[10pt,a4paper]{report}
\usepackage[latin1]{inputenc}
\usepackage{amsmath}
\usepackage{amsfonts}
\usepackage{amssymb}
\usepackage{graphicx}
\usepackage{subfiles}
\graphicspath{ {F:/Master/V/Thesis/Document/img/} }
\begin{document}
    Hello
    \subfile{./tex/subtest.tex}
\end{document}

And for subtest.tex

%subtest.tex
\documentclass[F:/Master/V/Thesis/Document/Test.tex]{subfiles}
\begin{document}
Test text
    \begin{figure}[h]
        \centering
        \includegraphics[width=1\textwidth]{hierarchy}
        \caption{Hierarchy}
        \label{fig:hier}
    \end{figure}
\end{document}

The code runs when I don't include the figure, however if I include the figure the code doesn't compile and (I am using TeXstudio) there is no message in the log other than Process exited with error(s).

How can I make it work so that it compiles with the figure in the subfile?