\documentclass[12pt]{article}
  \pagestyle{empty}
  
  \usepackage{amssymb}
  \usepackage{amsmath}
  \usepackage[usenames]{color}
  
  \begin{document}
  
  % No empty lines allowed in math block !
  \begin{align*}
  [% equation -%]
  \end{align*}
  
  \end{document}