Anzeigen aktualisieren erzeugt Fehler

SQLSTATE[HY000]: General error: 2014 Cannot execute queries while other unbuffered queries are active. Consider using PDOStatement::fetchAll(). Alternatively, if your code is only ever going to run against mysql, you may enable query buffering by setting the PDO::MYSQL_ATTR_USE_BUFFERED_QUERY attribute.
Stacktrace:
#0 /var/customers/webs/customer/wcf/lib/data/DatabaseObjectEditor.class.php(68): wcf\system\database\Database->prepareStatement('UPDATE\tgallery1...')
#1 /var/customers/webs/customer/gallery/lib/system/worker/ImageRebuildDataWorker.class.php(104): wcf\data\DatabaseObjectEditor->update(Array)
#2 /var/customers/webs/customer/wcf/lib/acp/action/WorkerProxyAction.class.php(93): gallery\system\worker\ImageRebuildDataWorker->execute()
#3 /var/customers/webs/customer/wcf/lib/action/AbstractAction.class.php(49): wcf\acp\action\WorkerProxyAction->execute()
#4 /var/customers/webs/customer/wcf/lib/action/AJAXInvokeAction.class.php(63): wcf\action\AbstractAction->__run()
#5 /var/customers/webs/customer/wcf/lib/system/request/Request.class.php(58): wcf\action\AJAXInvokeAction->__run()
#6 /var/customers/webs/customer/wcf/lib/system/request/RequestHandler.class.php(139): wcf\system\request\Request->execute()
#7 /var/customers/webs/customer/acp/index.php(10): wcf\system\request\RequestHandler->handle('wbb', true)
#8 {main}