Currently the needed extra definitions for MathJax usage (i.e. `\newcommand` and `\def` commaonds) are distributed over the header file and in a number of source code files.
Doxygen has the possibility for a centralize this by means of the MATHJAX_CODEFILE configuration setting, this has been implemented.
I have verified in the template in Doxygen 1.8.13 and that line does not
exist.
... And it makes the script crash and report an error in the browser
console.