\usepackage{eurosym}
\usepackage{tabularx}
\usepackage{ifthen}
-\usepackage[latin1]{inputenc}
+\usepackage[utf8]{inputenc}
\begin{document}
\setlength{\parindent}{0cm}
\rightline{\LARGE\textbf{\textit{Gutschrift}}} \vspace*{0.2cm}
\rightline{\large\textbf{\textit{Nr. <%invnumber%>% \vspace*{0.2cm}
}}}
+ für Rechnung: \hfill <%invnumber_for_credit_note%>
Gutschriftdatum:\hfill <%invdate%>