Pandoc 1.15.0.6: Error making user defined call [latex source]

[eteep]

Error is:

pandoc:
Error at "input" (line 155, column 10):
unexpected '}'
expecting letter, lf new-line, "%", "\\", "{", "-", "``", "\8220",
"\"`", "\"", "`", "\8216", "''", "\8221", "'", "\8217", "~", "$$", "$",
"^^", "&", white space or end of input

         ^

attached as effected.tex is the tex source producing the error

The error does not exist when the user defined calls \halftitlepage and
\titleM are removed

attached as fudged.tex

Any ideas?

Thanks all.