今天更新后出现了一个问题，我将其追溯到 mathrsfs 包。这个文件\usepackage{mathrsfs}注释掉后可以正常工作，但\usepackage{mathrsfs}放回去后就失败了
\documentclass{amsart}
%\usepackage{mathrsfs}
\begin{document}
a
\end{document}
准确地说，我正在使用 MiKTeX Revision 2.9.6809，并在文件上运行 PDFTeXify。
当我尝试使用 mathrsfs 时，它会生成以下错误消息，并且不会生成 PDF：
This is BibTeX, Version 0.99d (MiKTeX 2.9.6880 64-bit)
The top-level auxiliary file: What.aux
I found no \citation commands---while reading file What.aux
I found no \bibdata command---while reading file What.aux
I found no \bibstyle command---while reading file What.aux
(There were 3 error messages)
Command Line: pdflatex.exe --interaction=errorstopmode --synctex=-1 "What.tex"
Startup Folder: C:\Users\User\Documents\TeX_Files\Cohomology_foundations
This is pdfTeX, Version 3.14159265-2.6-1.40.19 (MiKTeX 2.9.6880 64-bit)
entering extended mode
(What.tex
LaTeX2e <2018-12-01>
("C:\Program Files\MiKTeX 2.9\tex\latex\amscls\amsart.cls"
Document Class: amsart 2017/10/31 v2.20.4
("C:\Program Files\MiKTeX 2.9\tex\latex\amsmath\amsmath.sty"
For additional information on amsmath, use the `?' option.
("C:\Program Files\MiKTeX 2.9\tex\latex\amsmath\amstext.sty"
("C:\Program Files\MiKTeX 2.9\tex\latex\amsmath\amsgen.sty"))
("C:\Program Files\MiKTeX 2.9\tex\latex\amsmath\amsbsy.sty")
("C:\Program Files\MiKTeX 2.9\tex\latex\amsmath\amsopn.sty"))
("C:\Program Files\MiKTeX 2.9\tex\latex\amsfonts\umsa.fd")
("C:\Program Files\MiKTeX 2.9\tex\latex\amsfonts\amsfonts.sty"))
("C:\Program Files\MiKTeX 2.9\tex\latex\jknappen\mathrsfs.sty") (What.aux)
("C:\Program Files\MiKTeX 2.9\tex\latex\amsfonts\umsa.fd")
("C:\Program Files\MiKTeX 2.9\tex\latex\amsfonts\umsb.fd")
("C:\Program Files\MiKTeX 2.9\tex\latex\jknappen\ursfs.fd")
! Font U/rsfs/m/n/8=rsfs10 at 8.0pt not loadable: Bad metric (TFM) file.
<to be read again>
relax
l.4 \begin{document}
?
Process has been terminated ...
我的 MiKTeX 控制台显示 jknappen 仍处于安装状态，并且 jknappen 文件夹中有 mathrsfs。有人能帮我重新使用该包吗？