Clicking on "Download your certificate" button opens a new browser tab, and the resulting page is blank.
I turned on error reporting to "development", and the following error codes were shown (note: hosting path info truncated to ...) :
Warning: require_once(.../public_html/components/com_cjlib/lib/tcpdf/config/lang/eng.php): failed to open stream: No such file or directory in .../public_html/components/com_communityquiz/helpers/tcpdf.php on line 11
Fatal error: require_once(): Failed opening required '.../public_html/components/com_cjlib/lib/tcpdf/config/lang/eng.php' (include_path='.:/usr/share/php') in .../public_html/components/com_communityquiz/helpers/tcpdf.php on line 11
I took a look in directory "/public_html/components/com_cjlib/lib/tcpdf/config/" and the "lang" folder is missing. The only thing in the config folder is "tcpdf_config.php".
This is a brand new installation of pkg_cjlib_v2.8.3, pkg_communityquiz_v4.8.1