Hyperref and ulem commands cannot be combined

Package ulem has restrictions, what can be used inside the argument. Thus \hypertarget cannot be used directly.

It can be protected via \mbox:

\sout{\mbox{\hypertarget{...}{...}}

Or a better solution, would be to switch \sout with \hypertarget:

\hypertarget{label}{\sout{text}}

Complete example:

\documentclass{article}

\usepackage[normalem]{ulem}
\usepackage{hyperref}

\begin{document}
\sout{\mbox{\hypertarget{label}{text}}}
\hypertarget{label2}{\sout{text2}}
\end{document}