Brett on 28 Apr, 2018 04:29 PM
It appears that selecting TeX-AMS-MML_SVG in the MathJax configuration
dropdown fixes the issue. I am by no means a MathJax expert (and
honestly, I don't know what half of the MathJax config settings mean).
It seems, though, that the MML-AM configuration that you have selected
is unable to process the apostrophe character as a valid symbol.