Fatal error: Uncaught Error: Class 'SimpleXMLElement' not found in /var/www/html/jurnal/plugins/generic/citationStyleLanguage/lib/vendor/seboettg/citeproc-php/src/Locale/Locale.php:60 Stack trace: #0 /var/www/html/jurnal/plugins/generic/citationStyleLanguage/lib/vendor/seboettg/citeproc-php/src/CiteProc.php(209): Seboettg\CiteProc\Locale\Locale->__construct('en-US') #1 /var/www/html/jurnal/plugins/generic/citationStyleLanguage/lib/vendor/seboettg/citeproc-php/src/CiteProc.php(168): Seboettg\CiteProc\CiteProc->init(false) #2 /var/www/html/jurnal/plugins/generic/citationStyleLanguage/CitationStyleLanguagePlugin.inc.php(423): Seboettg\CiteProc\CiteProc->render(Array, 'bibliography') #3 /var/www/html/jurnal/plugins/generic/citationStyleLanguage/pages/CitationStyleLanguageHandler.inc.php(45): CitationStyleLanguagePlugin->getCitation(Object(Request), Object(Submission), 'harvard-cite-th...', Object(Issue), Object(Publication)) #4 /var/www/html/jurnal/lib/pkp/classes/core/PKPRouter.inc.php(395): CitationStyleLanguageHandler->get in /var/www/html/jurnal/plugins/generic/citationStyleLanguage/lib/vendor/seboettg/citeproc-php/src/Locale/Locale.php on line 60