Wordpress logs Database errors

[pzzz]

Since my Wordpress update to 4.7.4, my Apache error log shows messages for each write operation:

WordPress-Datenbank-Fehler f\xc3\xbcr Abfrage DELETE FROM wp_jobwall_wp WHERE id = '5' von do_action('toplevel_page_jobwall-wp-admin'), WP_Hook->do_action, WP_Hook->apply_filters, jobwall_wp_Admin::menu_manage_jobwall, jobwall_wp_Admin::delete_job, referer: http://localhost/wordpress/wp-admin/admin.php?page=jobwall-wp-admin

WordPress-Datenbank-Fehler f\xc3\xbcr Abfrage INSERT INTO wp_jobwall_wp (title, shortDescription,\n \t\tcompanyName, companyLogoUrl, locationCityName,\n \t\tlocationZipCode, locationStreetWithStreetnumber,\n \t\tisStartup, jobType, linkToJobPage)\n VALUES ('Hiwi am CIE gesucht', 'Zur Verst\xc3\xa4rkung unseres Teams am CIE suchen wir ab sofort eine wissenschaftliche Hilfskraft.', 'CIE', 'http://test.cie-kit.de/wp-content/uploads/2015/10/Logo_CIE_IMA-KIT_4C_2013_ohneText.png', 'Karlsruhe', 76131, 'Engesserstra\xc3\x9fe 9', 0, 'Teilzeitstelle', 'http://www.cie-kit.de/hiwi-am-cie-gesucht/') von do_action('jobwall_page_jobwall-wp-admin-add'), WP_Hook->do_action, WP_Hook->apply_filters, jobwall_wp_Admin::menu_manage_jobwall_add, jobwall_wp_Admin::add_job, referer: http://localhost/wordpress/wp-admin/admin.php?page=jobwall-wp-admin-add

Despite the error messages the operations seem to complete successfully, so I think for the moment we might ignore them and fix them later.