LaTeX Error: Environment keywords undefined

Define your own \keywords macro:

enter image description here

\title{My title}
\author{My author}
\providecommand{\keywords}[1]{\textbf{\textit{Index terms---}} #1}
Lorem ipsum\ldots
\keywords{one, two, three, four}


I use \providecommand instead of \newcommand to accommodate the possibility that the document class you're using has defined \keywords already. \providecommand will only define it if not already defined.


One, two, three, four, five


my files from the logfile:

 *File List*
 article.cls    2007/10/19 v1.4h Standard LaTeX document class
  size10.clo    2007/10/19 v1.4h Standard LaTeX file (size option)
  ot1ptm.fd    2001/06/04 font definitions for OT1/ptm.