Miktex font errors

Question

I use miktex 2.9

\documentclass{beamer}
\usepackage{parskip}
\usepackage{amsmath}
\usepackage{amssymb}
\usepackage{amsthm}
\usepackage{txfonts}
\usepackage{pxfonts} 
\usepackage{tabularx}
\usepackage{graphicx}
\usepackage{caption}
\usepackage{subcaption}
\usepackage{longtable}
\usepackage{ragged2e}
\usepackage{eso-pic}
\usetheme{Madrid}
\begin{document}
\begin{frame}
\begin{eqnarray}
p(y)=\frac{\kappa b^{\lambda}}{\Gamma(\lambda)}e^{-by^{-\kappa}}y^{-(\kappa\lambda+1)}.
\end{eqnarray}
\end{frame}
\end{document}

I got the following errors:

Running miktex-makemf.exe... miktex-makemf: The rpxmi source file could not be found.

Running ttf2pk.exe... miktex-makepk: PK font rpxmi could not be created. ) (see the transcript file for additional information) !pdfTeX error: C:\Program Files (x86)\MiKTeX 2.9\miktex\bin\pdflatex.EXE (file rpxmi): Font rpxmi at 360 not found ==> Fatal error occurred, no output PDF file produced! texify: pdflatex failed for some reason (see log file).

Please help.

Thanks