初めて質問をさせていただきます。
以前のTex（2013年バージョン）ではコンパイルできた以下のファイルが、
最新版のTex （2019年バージョン）では以下のエラーが出てきてしまいます。
どうしたらいいのでしょうか。
emathとschlmathも最新版をダウンロード済みです。
\documentclass[b4paper,11pt,twocolumn,fleqn,dvipdfmx]{jarticle}
\usepackage{epic,eepic,amssymb,amsmath,schlmath}
\usepackage[dvipdfmx,hiresbb]{graphicx}
\usepackage{wrapfig}
\usepackage[utf8]{inputenc}
\Shiken
\setlength{\columnseprule}{0.4pt}
\setlength{\columnsep}{2zw}
\def\labelenumi{\bf\theenumi.}
\def\theenumii{\arabic{enumii}}
\setlength{\mathindent}{1cm}
\newcounter{r1}
\setcounter{r1}{1}
\pagestyle{empty}
\def\HIDDEN{0}
\begin{document}
\name{}{}
%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
\twocolumn[
\underline{
{\Large 高校I年数学 No.1/3}
\hskip1zw \hfill
{\Large ３年 \hskip2zw 組(\hskip2zw) 氏名: \hskip30ex}}
\vspace*{2ex}
\mbox{} ]
\Toi 次の各数の正の約数の個数を求めよ。
\SubToi $60$
\vfill
\SubToi $2600$
\end{document}
エラーメッセージ
This is ptex2pdf[.lua] version 20181212.0.
Processing 2019.tex
This is e-pTeX, Version 3.14159265-p3.8.2-190131-2.6 (utf8.sjis) (TeX Live 2019/W32TeX) (preloaded format=platex)
restricted \write18 enabled.
entering extended mode
(./2019.tex
pLaTeX2e <2019-04-06> (based on LaTeX2e <2018-12-01>)
(c:/w32tex/share/texmf-dist/tex/platex/base/jarticle.cls
Document Class: jarticle 2019/04/02 v1.8b Standard pLaTeX class
(c:/w32tex/share/texmf-dist/tex/latex/base/fleqn.clo)
(c:/w32tex/share/texmf-dist/tex/platex/base/jsize11.clo))
(c:/w32tex/share/texmf-dist/tex/latex/eepic/epic.sty
Enhancements to Picture Environment. Version 1.2 - Released June 1, 1986
) (c:/w32tex/share/texmf-dist/tex/latex/eepic/eepic.sty
Extension to Epic and LaTeX. Version 1.1e - Released Dec 21, 1999
) (c:/w32tex/share/texmf-dist/tex/latex/amsfonts/amssymb.sty
(c:/w32tex/share/texmf-dist/tex/latex/amsfonts/amsfonts.sty))
(c:/w32tex/share/texmf-dist/tex/latex/amsmath/amsmath.sty
For additional information on amsmath, use the `?' option.
(c:/w32tex/share/texmf-dist/tex/latex/amsmath/amstext.sty
(c:/w32tex/share/texmf-dist/tex/latex/amsmath/amsgen.sty))
(c:/w32tex/share/texmf-dist/tex/latex/amsmath/amsbsy.sty)
(c:/w32tex/share/texmf-dist/tex/latex/amsmath/amsopn.sty))
(c:/w32tex/share/texmf-local/tex/platex/misc/emath/Schlmath.sty
高等学校数学用 pLaTeX2e 用マクロ集 Ver4.07.03 2008.01.10 求\GenericError {(inpu
tenc) }{Package inputenc Error: Invalid UTF-8 byte "AD}{See the
inputenc package documentation for explanation.}{The document does not appear t
o be in UTF-8 encoding.\MessageBreak Try adding \UseRawInputEncoding as the fir
st line of the file\MessageBreak or specify an encoding such as \usepackage [la
tin1]{inputenc}\MessageBreak in the document preamble.\MessageBreak Alternative
ly, save the file in UTF-8 using your editor or another tool}