数学模式：**！字体 OMX/cmex/m/n/6=cmex7 位于 6.0pt 处无法加载：错误的度量 (TFM) 文件

Question

我刚刚下载了 texstudio 编辑器。现在我直接遇到了问题。除了关键的数学模式外，到目前为止一切都运行良好。我输入了如下代码：

\documentclass[11
 pt,a4paper,twoside]{article}
\usepackage[utf8]{inputenc}
\usepackage{amsmath}
\usepackage{graphicx}
\author{}
\title{ }
\begin{document}

\begin{equation}
H \cdot x= p
\end{equation}
\end{document}

我尝试编译它但得到以下报告：

*

**! Font OMX/cmex/m/n/6=cmex7 at 6.0pt not loadable: Bad metric (TFM) file.
<to be read again> 
                   relax 
l.10  \begin{equation}

I wasn't able to read the size data for this font,
so I will ignore the font specification.
[Wizards can fix TFM files using TFtoPL/PLtoTF.]
You might try inserting a different font spec;
e.g., type `I\font<same font id>=<substitute font name>'.
! Math formula deleted: Insufficient extension fonts.
\endmathdisplay ...badmath \fi \endmathdisplay@a $
                                                  $\global \let \df@label \@...
l.12  \end{equation}

Sorry, but I can't typeset math unless \textfont 3
and \scriptfont 3 and \scriptscriptfont 3 have all
the \fontdimen values needed in math extension fonts.**

我不知道那里发生了什么，所以如果有人能帮助我我会非常高兴。