[PrestaShopDatabaseException]

Illegal mix of collations (utf8_general_ci,IMPLICIT) and (utf8_unicode_ci,IMPLICIT) for operation '='<br /><br /><pre>SELECT pr.`class` from `ps_appagebuilder_page` pa INNER JOIN `ps_appagebuilder_products` pr ON (pa.`page` = pr.`plist_key`) where pa.id_category = '54' AND pa.id_shop = '1' LIMIT 1</pre>
at line 769 in file classes/db/Db.php

764.         if ($webservice_call && $errno) {
765.             $dbg = debug_backtrace();
766.             WebserviceRequest::getInstance()->setError(500, '[SQL Error] ' . $this->getMsgError() . '. From ' . (isset($dbg[3]['class']) ? $dbg[3]['class'] : '') . '->' . $dbg[3]['function'] . '() Query was : ' . $sql, 97);
767.         } elseif (_PS_DEBUG_SQL_ && $errno && !defined('PS_INSTALLATION_IN_PROGRESS')) {
768.             if ($sql) {
769.                 throw new PrestaShopDatabaseException($this->getMsgError() . '<br /><br /><pre>' . $sql . '</pre>');
770.             }
771. 
772.             throw new PrestaShopDatabaseException($this->getMsgError());
773.         }
774.     }