fyi, Just posted this error for tex4ht
https://tex.stackexchange.com/questions/383129/tex4ht-gives-package-amsmath-error-tag-not-allowed-here Not sure if this is known or not? Should I create a bug report? There was a related issue https://puszcza.gnu.org.ua/bugs/?225 But it does not look they are same error, Or may be they are the same? Only when run with make4ht. No error with lualatex nor with pdflatex. MWE: --------------------- \documentclass[11pt]{article} \usepackage{amsmath} \begin{document} \[ x=y \tag{1} \] \end{document} -------------------------
make4ht foo.tex
..... LaTeX2e <2017/01/01> patch level 3 Babel <3.9r> and hyphenation patterns for 83 language(s) loaded. (./foo.tex (/usr/local/texlive/2016/texmf-dist/tex/latex/base/article.cls Document Class: article 2014/09/29 v1.4h Standard LaTeX document class (/usr/local/texlive/2016/texmf-dist/tex/latex/base/size11.clo)) .... (/usr/local/texlive/2016/texmf-dist/tex/generic/tex4ht/html4.4ht) (/usr/local/texlive/2016/texmf-dist/tex/generic/tex4ht/html4-math.4ht)) (/usr/local/texlive/2016/texmf-dist/tex/generic/tex4ht/html4.4ht) (/usr/local/texlive/2016/texmf-dist/tex/generic/tex4ht/html4-math.4ht)) (./foo.aux) ! Package amsmath Error: \tag not allowed here. See the amsmath package documentation for explanation. Type H <return> for immediate help. ... l.7 x=y \tag {1} ? which make4ht /usr/local/texlive/2016/texmf-dist/scripts/make4ht/make4ht I changed the code to use \begin{align} etc... and now tex4ht does not complain about \tag any more --Nasser