1
   \documentclass[bibliography=totoc, parskip=half, DIV=calc, 12pt, captions=tableheading]{scrartcl} 

   \usepackage{polyglossia}

   \setdefaultlanguage{german}

   \usepackage[autostyle=true,german=quotes]{csquotes} 

   \usepackage{graphicx}

   \usepackage[headsepline]{scrlayer-scrpage}

   \pagestyle{scrheadings}

   %\usepackage[style=numeric,backend=biber, natbib=true]{biblatex}

   %\addbibresource{nes.bib}

   \usepackage{booktabs}  

   \usepackage{romanbar}

   \usepackage[breaklinks=true]{hyperref}

   \usepackage{amsthm,amsmath,amssymb}

   \newtheorem{theorem}{Satz}

Can anybody see where I made the mistake that leads to this error?

Browse other questions tagged or ask your own question.