\documentclass{book}
\usepackage{amsmath}
\usepackage[german]{babel}
\usepackage{amssymb}
\usepackage{amsxtra}
\usepackage[dvips]{epsfig,psfrag}
\usepackage{listings}
....
this is how my file starts. I didn't even edit it, I received it like this. However, if I want to make a pdf, it gives me the undefined control
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