xsim mit tcolorbox - Rückgabewert 1 beendet

\documentclass{scrartcl}

\usepackage[ngerman]{babel}
\usepackage[utf8]{inputenc}
\usepackage{tcolorbox}
\usepackage{xsim}

%Aufgabenumgebung
\DeclareExerciseEnvironmentTemplate{tcolorbox}
{%
\tcolorbox[standard jigsaw,
opacityback=0,
opacityframe=0,
coltitle=black,
breakable ,
drop shadow ,
beforeafter skip = .5\baselineskip ,
title = 
\textbf{\GetExerciseName~\GetExerciseProperty{counter}}%
\GetExercisePropertyT{subtitle}{ \textit{\PropertyValue}}%
\IfInsideSolutionF{%
\GetExercisePropertyT{points}{ % notice the space
(%
\printgoal{\PropertyValue}
\IfExerciseGoalSingularTF{points}
{\XSIMtranslate{point}}
{\XSIMtranslate{points}}%
)%
}%
}%
]%
}
{\endtcolorbox}

\DeclareExerciseType{klausuraufgabe}{
exercise-env = aufgabe ,
solution-env = loesung ,
exercise-name = Aufgabe ,
solution-name = Loesung ,
exercise-template = tcolorbox ,
solution-template = tcolorbox
}

\begin{document}

\begin{aufgabe}[points=2+2+2]
 Das ist eine Aufgabe.
\end{aufgabe}

\end{document}