Code for 2 column pdf in Rmarkdown ceases to work when moving between machines




I am trying to produce a pdf with a 2 column format. I found online a bit of code that allows one to "trick" Rmarkdown into producing two column pdfs.


However, in moving from one machine to another, the code does not work. The error I get is:

! Undefined control sequence.
l.106 \Begin

my complete header information is below. Any advice on why the code would work on one Windows 10 machine and not another would be helpful. RStudio version is 1.1.442. R version is 3.5.1.

Amer (new to markdown and to R)

title: "`blah"
author: "Blah"
    latex_engine: xelatex
    fig_caption: yes
    keep_tex: yes
fontsize: 8pt
geometry: "left=1.5cm,right=1cm,top=2cm,bottom=2.2cm"
header-includes: \usepackage{fancyhdr} 
  \usepackage{booktabs,xcolor} \pagestyle{fancy}
  \rhead{October 2018}