The DPL extension (version 2.3.0) produced a SQL statement which lead to a Database error.
The reason may be an internal error of DPL or an error which you made,
especially when using DPL options like titleregexp.
Query text is:
SELECT DISTINCT `lit_page`.page_namespace AS page_namespace,`lit_page`.page_title AS page_title,`lit_page`.page_id AS page_id, `lit_page`.page_title AS sortkey, `lit_page`.page_counter AS page_counter FROM `lit_page` INNER JOIN `lit_categorylinks` AS cl0 ON `lit_page`.page_id=cl0.cl_from AND (cl0.cl_to='Buchcovers') WHERE 1=1 AND `lit_page`.page_namespace IN ('0') AND `lit_page`.page_is_redirect=0 ORDER BY page_title ASC LIMIT 500 OFFSET 0

Error message is:
Unknown column 'lit_page.page_counter' in 'field list' (ub-mysql01.unibe.ch)