fancy-preview script "Fatal error occurred, no output PDF file produced!"

I have some problem using the fancy-preview script. For all MWE found on http://user.mendelu.cz/marik/fancy-preview/ e.g.,

documentclass{article}
usepackage{amsmath,amsthm}
newtheorem{theorem}{Lemma}
usepackage{xcolor}
usepackage{biblatex}
usepackage{hyperref} % Important!

bibliography{biblio}

usepackage[inactive]{fancytooltips}
begin{document}

This is system.

begin{theorem}[Lemma from xxx]label{lemma}
  If $k<0$, then
  begin{equation}
    label{eq:1}
    x^2+k<x^2
  end{equation}
  for every real number $x$.
end{theorem}


Inequality eqref{eq:1} in Lemma ref{lemma} can be proved easily. Is
more general xxx.

begin{equation}
    label{eq:2}
    x^2+k_1<x^2
end{equation}


clearpage
See Lemma~ref{lemma}, equation~(ref{eq:1}). Compare also (ref{eq:2}).
end{document}

I get the following error when running fancy-preview

!pdfTeX error: pdflatex: cannot find image file
 ==> Fatal error occurred, no output PDF file produced!