不知何故，我的 LaTeX 突然开始出现以下错误。我已经在这台 Linux 机器（Fedora 14）上使用 LaTeX 两年了，没有出现任何问题。我以前从未见过此错误，而且据我所知，LaTeX 文件没有更改过。有人能向我解释发生了什么以及我该怎么办吗？谢谢。
Xy-pic option: Frame and Bracket extension v.3.14 loaded)
(/usr/share/texmf/tex/latex/yliow/download/xy-3.8.8/texinputs/xycmtip.tex
Xy-pic option: Computer Modern tip extension v.3.7
(/usr/share/texmf/tex/latex/yliow/download/xy-3.8.8/texinputs/xytips.tex
Xy-pic option: More Tips extension v.3.9
! Font \xy@@alfont=xyluat10 not loadable: Metric (TFM) file not found.
<to be read again>
\def
l.35 \xyfont@\xy@@blfont
=xylubt10
! ==> Fatal error occurred, no output PDF file produced!
乳胶代码：
\documentclass[a4paper,12pt]{scrbook}
\usepackage{amsmath,amssymb,amsthm}
\usepackage{parskip}
\usepackage{lastpage}
\usepackage{color,graphicx}
\usepackage{pgf}
\usepackage[all]{xy}
\usepackage{tikz}
\usetikzlibrary{arrows}
\usepackage{pgf,pgfarrows,pgfnodes}
\begin{document}
\thispagestyle{empty}
\begin{center}
\begin{tikzpicture}
\draw[line width=0.04cm,black,<-] (0.0,0.0) -- (1.0,1.0);
\draw[line width=0.1cm,red,->] (3.0,0.0) -- (6.0,2.0);
\draw[line width=0.2cm,red,<->,dashed] (6.0,0.0) -- (9.0,2.0);
\draw[line width=0.1cm,blue,|<->|] (9.0,0.0) -- (12.0,2.0);
\draw[line width=0.05cm,blue,<<->>] (12.0,0.0) -- (15.0,2.0);
\draw[gray] (0.0,0.0) -- (0.0,2);
\draw[gray] (1.0,0.0) -- (1.0,2);
\draw[gray] (2.0,0.0) -- (2.0,2);
\draw[gray] (3.0,0.0) -- (3.0,2);
\draw[gray] (4.0,0.0) -- (4.0,2);
\draw[gray] (5.0,0.0) -- (5.0,2);
\draw[gray] (6.0,0.0) -- (6.0,2);
\draw[gray] (7.0,0.0) -- (7.0,2);
\draw[gray] (8.0,0.0) -- (8.0,2);
\draw[gray] (9.0,0.0) -- (9.0,2);
\draw[gray] (10.0,0.0) -- (10.0,2);
\draw[gray] (11.0,0.0) -- (11.0,2);
\draw[gray] (12.0,0.0) -- (12.0,2);
\draw[gray] (13.0,0.0) -- (13.0,2);
\draw[gray] (14.0,0.0) -- (14.0,2);
\draw[gray] (15.0,0.0) -- (15.0,2);
\draw[gray] (0.0,0.0) -- (15,0.0);
\draw[gray] (0.0,1.0) -- (15,1.0);
\draw[gray] (0.0,2.0) -- (15,2.0);
\draw(0, 0) node [font=\ttfamily, label=below:{\texttt{0}}] {};
\draw(1, 0) node [font=\ttfamily, label=below:{\texttt{1}}] {};
\draw(2, 0) node [font=\ttfamily, label=below:{\texttt{2}}] {};
\draw(3, 0) node [font=\ttfamily, label=below:{\texttt{3}}] {};
\draw(4, 0) node [font=\ttfamily, label=below:{\texttt{4}}] {};
\draw(5, 0) node [font=\ttfamily, label=below:{\texttt{5}}] {};
\draw(6, 0) node [font=\ttfamily, label=below:{\texttt{6}}] {};
\draw(7, 0) node [font=\ttfamily, label=below:{\texttt{7}}] {};
\draw(8, 0) node [font=\ttfamily, label=below:{\texttt{8}}] {};
\draw(9, 0) node [font=\ttfamily, label=below:{\texttt{9}}] {};
\draw(10, 0) node [font=\ttfamily, label=below:{\texttt{10}}] {};
\draw(11, 0) node [font=\ttfamily, label=below:{\texttt{11}}] {};
\draw(12, 0) node [font=\ttfamily, label=below:{\texttt{12}}] {};
\draw(13, 0) node [font=\ttfamily, label=below:{\texttt{13}}] {};
\draw(14, 0) node [font=\ttfamily, label=below:{\texttt{14}}] {};
\draw(15, 0) node [font=\ttfamily, label=below:{\texttt{15}}] {};
\draw(0, 0) node [font=\ttfamily, label=left:{\texttt{0}}] {};
\draw(0, 1) node [font=\ttfamily, label=left:{\texttt{1}}] {};
\draw(0, 2) node [font=\ttfamily, label=left:{\texttt{2}}] {};
\end{tikzpicture}
\end{center}
\end{document}