Hello,
the newest update of expl3 breaks xtemplate:

\documentclass{minimal}
\usepackage{xtemplate}
\DeclareObjectType{test}{0}
\DeclareTemplateInterface{test}{test}{0}{a:tokenlist={}}
\begin{document}
\null
\end{document}

results in

! Undefined control sequence.
\xtemplate_parse_keys_elt_aux:n #1->\tl_if_eq:VnT 
                                                  \l_xtemplate_keytype_tl {#...

Regards,
Philipp