DB Error: Illegal mix of collations (latin1_swedish_ci,IMPLICIT) and (utf8mb4_general_ci,COERCIBLE) for operation '='

Stack Trace:

File: /var/www/rechts/ejournal/classes/article/AuthorDAO.inc.php line 63
Function: DAO->retrieve("SELECT DISTINCT aa.submission_id FROM authors aa LEFT...", Array(7))

File: /var/www/rechts/ejournal/pages/search/SearchHandler.inc.php line 180
Function: AuthorDAO->getPublishedArticlesForAuthor("1", "Arfan", "Faiz", "Muhlizi", "Pusat Peneli Ɵ an dan Pengembangan Sistem Hukum Nasional Ba...", "ID")

File: (unknown) line (unknown)
Function: SearchHandler->authors(Array(1), Object(Request))

File: /var/www/rechts/ejournal/lib/pkp/classes/core/PKPRouter.inc.php line 362
Function: call_user_func(Array(2), Array(1), Object(Request))

File: /var/www/rechts/ejournal/lib/pkp/classes/core/PKPPageRouter.inc.php line 220
Function: PKPRouter->_authorizeInitializeAndCallRequest(Array(2), Object(Request), Array(1), False)

File: /var/www/rechts/ejournal/lib/pkp/classes/core/Dispatcher.inc.php line 134
Function: PKPPageRouter->route(Object(Request))

File: /var/www/rechts/ejournal/lib/pkp/classes/core/PKPApplication.inc.php line 178
Function: Dispatcher->dispatch(Object(Request))

File: /var/www/rechts/ejournal/index.php line 66
Function: PKPApplication->execute()