"Too many symbol fonts declared" error

Question

I've had this problem for a while. When I try to add a new package, it says

! LaTeX Error: Too many symbol fonts declared.

See the LaTeX manual or LaTeX Companion for explanation. Type H for immediate help. ...

l.88 \DeclareSymbolFont{stmry}{U}{stmry}{m}{n}

I had to give up using some of the packages that I wanted to use. I've searched for the problem, and what I understood was that there are some limitations to the fonts declaration. I wanted to know what exactly the problem is and if there are any solutions to the problem.

\documentclass[openany,english]{scrbook}
\usepackage[utf8]{inputenc}
\usepackage[T1]{fontenc}

\usepackage{newtxtext}
\usepackage[nonewtxmathopt]{newtxmath}
\usepackage{bm}    
\usepackage{esvect}

%With verbatim package, using \wcheck from mathabx package
\usepackage{verbatim}

\DeclareFontFamily{U}{mathx}{\hyphenchar\font45}
\DeclareFontShape{U}{mathx}{m}{n}{
      <5> <6> <7> <8> <9> <10>
      <10.95> <12> <14.4> <17.28> <20.74> <24.88>
      mathx10
      }{}
\DeclareSymbolFont{mathx}{U}{mathx}{m}{n}
\DeclareFontSubstitution{U}{mathx}{m}{n}
\DeclareMathAccent{\wcheck}{0}{mathx}{"71}
\DeclareMathAccent{\wideparen}{0}{mathx}{"75}

\def\cs#1{\texttt{\char`\\#1}}
%

%Using \bigtimes,\bigoplus from mathabx
\DeclareMathSymbol{\bigplus}{1}{mathx}{"90}
\DeclareMathSymbol{\bigtimes}{1}{mathx}{"91}
%

\usepackage{amsmath, amssymb, graphicx}
\usepackage{stmaryrd}       % \lightning

\begin{document}
hey
\end{document}

I use stmaryrd package for \lightning. The usage of verbatim package was copied from other tex.stackexchange question and modified slightly(I think I added one more \DeclareMathAccent). The last two \DeclareMathSymbol do not affect this problem, but I added them for their relationship with mathx. esvect is the package I tried to add this time.

I'm not an expert, so I usually search for my problems and use the corresponding packages. So I'm really not sure if my usage of packages has become inefficient or not. My guess is that I tried avoiding mathx from changing all the fonts but it brought limitations. What is the best solution in this case?

Answer 1

If you are not particular about which \lightning symbol you use, you can substitute

\usepackage{stmaryrd} %\lightning

for

\usepackage{marvosym} %\Lightning

Or for another one with a lightning symbol, you can check page 101 from The Comprehensive LaTeX Symbol List to see other similar symbols. I don't know what other packages you need to add so this might not be a complete solution, but I did add a bunch of random packages to the document and using marvosym worked for me.