Dirty workaround: copy download-page-clean.php from wp-content/plugins/download-manager/tpls3/ to wp-content/plugins/download-manager/tpls/
workaround: copy download-page-clean.php from wp-content/plugins/download-manager/tpls3/ to wp-content/plugins/download-manager/tpls/
This is a must have. 1+