Unknown column 'de' in 'where clause'

SELECT rel.* FROM xt_relations as rel WHERE target_content_type=270 AND target_content_id IN(de/Parteileitung_10135) AND content_type=5100 ORDER by position

In File: /var/www/vhosts/fdp-sg.ch/httpdocs/xt/plugins/ch.iframe.snode.relations/list/index.php
On Line: 37
Fatal error: Call to a member function fetchrow() on a non-object in /var/www/vhosts/fdp-sg.ch/httpdocs/xt/includes/classes/xt.class.php on line 436