Line 1185:

("\$^\\|[^\\\\]\$\$\\\\\\\\\$*[?$]\$[#\"'`]\$" 3 (1 . nil))

A workaround (with, to me, uknown consequences) is to remove the question mark from the line, like this:

("\$^\\|[^\\\\]\$\$\\\\\\\\\$*[$]\$[#\"'`]\$" 3 (1 . nil))