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## 编译环境
操作系统
* [x ] Windows 7/8/10
* [ ] macOS
* [ ] Linux
`若需勾选，请把[ ]改成[x]`
Tex发行版
* [x ] TexLive `2020`
* [ ] MikTeX `版本号`
* [ ] CTeX
`若需勾选，请把[ ]改成[x]`
## 我的问题
最简单的一段文档
```\documentclass{article}
\usepackage[UTF8]{ctex}
\begin{document}
zhfdf
\end{document}```
如果不加使用ctex的宏包，那么会正常编译通过，但加上宏包就会报错，如下：
```
(c:/Users/LibraFFly/libraffly/softWare/latex/texlive/2020/texmf-dist/tex/latex/
l3kernel/expl3.sty
! Undefined control sequence.
l.58 \cs
_if_exist:NF \c__expl_def_ext_tl
```
这个报错是用的自带的Texworks软件，如果用TexStudio会报更多的错误，但最先出现错误的就是expl3.sty，如下：
```
行 58: Undefined control sequence. \cs
行 58: Missing $ inserted. \cs_
行 58: Missing \begin{document}. \cs_
行 58: Double subscript. \cs_if_exist:NF \c__
行 59: Undefined control sequence. { \tl
行 59: Double subscript. { \tl_const:Nn \c__
行 60: Undefined control sequence. \cs
行 60: You can't use `macro parameter character #' in math mode. ...d:Npn \__kernel_sys_configuration_load:n #
行 63: Undefined control sequence. \cs
行 63: You can't use `macro parameter character #' in math mode. \cs_undefine:c { ver@ #
行 67: Argument of \@onefilewithoptions has an extra }. }
行 67: Paragraph ended before \@onefilewithoptions was complete. }
行 67: Missing $ inserted. }
行 67: Missing } inserted. }
行 67: Too many }'s. }
行 68: Undefined control sequence. \cs
行 68: Missing $ inserted. \cs_
行 68: Missing \begin{document}. \cs_
行 68: You can't use `macro parameter character #' in math mode. ...n \__kernel_sys_configuration_load_std:n #
行 70: Undefined control sequence. \cs
行 70: You can't use `macro parameter character #' in math mode. \cs_undefine:c { ver@ #
行 73: Argument of \@onefilewithoptions has an extra }. }
行 73: Paragraph ended before \@onefilewithoptions was complete. }
行 73: Missing $ inserted. }
行 73: Missing } inserted. }
行 73: Too many }'s. }
行 74: Undefined control sequence. \cs
行 74: Missing $ inserted. \cs_
行 74: Missing \begin{document}. \cs_
行 74: Missing { inserted. \cs_if_exist:NF \l__
行 75: Undefined control sequence. { \clist
行 75: Missing { inserted. { \clist_new:N \l__
行 79: Undefined control sequence. \keys
行 79: Double subscript. \keys_
行 83: Undefined control sequence. { \sys
行 83: You can't use `macro parameter character #' in math mode. { \sys_load_backend:n {#
行 86: Undefined control sequence. \sys
行 87: Undefined control sequence. \debug
行 89: You can't use `macro parameter character #' in math mode. driver .meta:n = { backend = #
行 91: Undefined control sequence. \sys
行 94: Undefined control sequence. \sys
行 95: Undefined control sequence. \debug
行 98: Undefined control sequence. = \g
行 98: Missing { inserted. = \g__
行 102: Undefined control sequence. \bool
行 102: Undefined control sequence. \bool_gset_true:N \g
行 102: Missing { inserted. \bool_gset_true:N \g__
行 103: Undefined control sequence. \sys
行 106: Undefined control sequence. \keys
行 106: Missing { inserted. \keys_set:nV { sys } \l__
行 107: Undefined control sequence. \str
行 108: Undefined control sequence. { \sys
行 109: Undefined control sequence. \cs
行 109: Undefined control sequence. \cs_if_exist:NT \@pushfilenameaux
行 111: Undefined control sequence. \cs
行 48: Missing $ inserted.
行 48: Missing } inserted.
行 48: Missing } inserted.
行 48: Missing } inserted.
行 48: Missing } inserted.
行 48: Missing } inserted.
行 48: Missing } inserted.
行 72: Missing $ inserted. \tl_clear_new:N \l_
行 72: Missing \begin{document}. \tl_clear_new:N \l_
行 72: Missing { inserted. \tl_clear_new:N \l__
行 73: Missing { inserted. \int_new:N \l__
行 74: Missing number, treated as zero. \box_
行 74: Missing { inserted. \box_new:N \l__
行 75: Missing { inserted. \dim_new:N \l__
行 76: Undefined control sequence. \cs
行 76: Undefined control sequence. \cs_new_protected:Npn \ctex
行 76: You can't use `macro parameter character #' in math mode. ...new_protected:Npn \ctex_file_wrapper:nnn #
行 76: You can't use `macro parameter character #' in math mode. ...w_protected:Npn \ctex_file_wrapper:nnn #1#
行 76: You can't use `macro parameter character #' in math mode. ...protected:Npn \ctex_file_wrapper:nnn #1#2#
行 78: Undefined control sequence. \use
行 81: Missing number, treated as zero. \char_
行 82: You can't use `macro parameter character #' in math mode. #
行 83: You can't use `macro parameter character #' in math mode. \exp_not:n {#
行 84: Undefined control sequence. \bool
行 84: Missing { inserted. \bool_if:NTF \l__
行 87: Missing number, treated as zero. \char_
行 87: Missing number, treated as zero. \char_set_catcode:nn { 64 } { \char_
行 88: You can't use `macro parameter character #' in math mode. #
行 91: Undefined control sequence. \cs
行 91: Undefined control sequence. \cs_new_protected_nopar:Npn \ctex
行 91: You can't use `macro parameter character #' in math mode. ...w_protected_nopar:Npn \ctex_file_input:n #
行 92: Undefined control sequence. { \ctex
行 92: Undefined control sequence. { \ctex_file_wrapper:nnn { } { \file
行 92: You can't use `macro parameter character #' in math mode. ...ex_file_wrapper:nnn { } { \file_input:n {#
行 93: Undefined control sequence. \cs
行 93: Undefined control sequence. \cs_new_protected_nopar:Npn \ctex
行 93: You can't use `macro parameter character #' in math mode. ...protected_nopar:Npn \ctex_scheme_input:n #
行 95: Undefined control sequence. \ctex
行 98: Undefined control sequence. \tl
行 98: Double subscript. \tl_if_exist:NTF \c__
行 100: Undefined control sequence. \file
行 100: You can't use `macro parameter character #' in math mode. ... \file_if_exist_input:nF { ctex-scheme- #
行 100: Double subscript. ...f_exist_input:nF { ctex-scheme- #1 - \c__
行 101: Undefined control sequence. { \file
行 101: You can't use `macro parameter character #' in math mode. ... { \file_input:n { ctex-scheme- #
行 103: Undefined control sequence. { \file
行 103: You can't use `macro parameter character #' in math mode. { \file_input:n { ctex-scheme- #
行 107: Undefined control sequence. \cs
行 107: Undefined control sequence. \cs_generate_variant:Nn \ctex
行 108: Undefined control sequence. \int_new:N \g
行 108: Missing { inserted. \int_new:N \g__
行 109: Undefined control sequence. \int_gset:Nn \g
行 109: Missing { inserted. \int_gset:Nn \g__
行 110: Undefined control sequence. \msg
行 111: You can't use `macro parameter character #' in math mode. { Support~package~`#
行 113: You can't use `macro parameter character #' in math mode. ...e~an~up~to~date~version~of~the~package~`#
行 116: Undefined control sequence. \sys
行 117: Undefined control sequence. { \cs
行 117: Undefined control sequence. { \cs_new_eq:NN \ifctexpdf
行 3: Incomplete \if; all text was ignored after line 117.
: Incomplete \if; all text was ignored after line 117.
行 58: Command \c invalid in math mode
行 59: Command \c invalid in math mode
行 58: Overfull \hbox (115.80017pt too wide) in paragraph
行 68: Overfull \hbox (20.03395pt too wide) in paragraph
行 74: Command \l invalid in math mode
行 75: Command \l invalid in math mode
行 106: Command \l invalid in math mode
行 107: Command \c invalid in math mode
行 48: Overfull \hbox (2088.27568pt too wide) in paragraph
行 98: Command \c invalid in math mode
行 100: Command \c invalid in math mode
```
重装了几次也不行，有没有大佬帮忙解决一下哇！谢谢！
