Fatal error: Uncaught Error: Class 'SimpleXMLElement' not found in /var/www/html/jurnals/plugins/generic/citationStyleLanguage/lib/vendor/seboettg/citeproc-php/src/Locale/Locale.php:60 Stack trace: #0 /var/www/html/jurnals/plugins/generic/citationStyleLanguage/lib/vendor/seboettg/citeproc-php/src/CiteProc.php(209): Seboettg\CiteProc\Locale\Locale->__construct('en-US') #1 /var/www/html/jurnals/plugins/generic/citationStyleLanguage/lib/vendor/seboettg/citeproc-php/src/CiteProc.php(168): Seboettg\CiteProc\CiteProc->init(false) #2 /var/www/html/jurnals/plugins/generic/citationStyleLanguage/CitationStyleLanguagePlugin.inc.php(423): Seboettg\CiteProc\CiteProc->render(Array, 'bibliography') #3 /var/www/html/jurnals/plugins/generic/citationStyleLanguage/CitationStyleLanguagePlugin.inc.php(277): CitationStyleLanguagePlugin->getCitation(Object(Request), Object(Submission), 'apa', Object(Issue), Object(Publication)) #4 /var/www/html/jurnals/lib/pkp/classes/plugins/HookRegistry.inc.php(107): CitationStyleLanguagePlugin->getArticleTem in /var/www/html/jurnals/plugins/generic/citationStyleLanguage/lib/vendor/seboettg/citeproc-php/src/Locale/Locale.php on line 60