SymbolFont

In the version of 3.08, the user feedbacks that when using with macropackages such as yhmath and esvect will encounter errors:

LaTeX Error:
  Too many symbol fonts declared.

The reason is that the template redefines the mathematical font to the maximum of 16 mathematical fonts, so it can't add mathematical fonts when calling other macro packages. To reduce the number of calls of unusual macropackages, how to use the yhmath and esvect macropackages is as follows.

Search yhmath or esvect in elegantbook.cls and uncomment the loading statement of macro packages you need.

%%% use yhmath pkg, uncomment following code
% \let\oldwidering\widering
% \let\widering\undefined
% \RequirePackage{yhmath}
% \let\widering\oldwidering

%%% use esvect pkg, uncomment following code
% \RequirePackage{esvect}