[Patrick]

Hi Steve,
I added the var_dump line and got following output showing the relative path:

string(22) “./class.customizer.php”
Warning: require_once(./class.customizer.php): failed to open stream: No such file or directory in /homepages/34/d560985172/htdocs/clickandbuilds/test/wp-content/plugins/conn1_card/card-default.php on line 325

Fatal error: require_once(): Failed opening required ‘./class.customizer.php’ (include_path=’.:/usr/lib/php7.0′) in /homepages/34/d560985172/htdocs/clickandbuilds/test/wp-content/plugins/conn1_card/card-default.php on line 325

(BTW, I temporary changed the permissions to 777 for all files inside the template folder. But this hasn’t changed anything)

Regards
Patrick