Fatal error: Uncaught Error: Call to a member function getId() on null in /var/www/html/lib/pkp/classes/publication/PKPPublication.inc.php:168 Stack trace: #0 /var/www/html/lib/pkp/classes/submission/PKPSubmission.inc.php(423): PKPPublication->getAuthorString(Array) #1 /var/www/html/cache/t_compile/e26d2de610226743d9feff244fb14ef53700227f^7cf1cd52b8ba8108de77f197078de34b733dd394_0.app.frontendobjectsarticle_summary.tpl.php(77): PKPSubmission->getAuthorString() #2 /var/www/html/lib/pkp/lib/vendor/smarty/smarty/libs/sysplugins/smarty_template_resource_base.php(123): content_68e7b9d1c9d815_38908810(Object(Smarty_Internal_Template)) #3 /var/www/html/lib/pkp/lib/vendor/smarty/smarty/libs/sysplugins/smarty_template_compiled.php(114): Smarty_Template_Resource_Base->getRenderedTemplateCode(Object(Smarty_Internal_Template)) #4 /var/www/html/lib/pkp/lib/vendor/smarty/smarty/libs/sysplugins/smarty_internal_template.php(384): Smarty_Template_Compiled->render(Object(Smarty_Internal_Template)) #5 /var/www/html/cache/t_compile/e26d2de610226743d9feff244fb14ef53700227f^26de9c47ced54328a8eb56e39bb4d4079aa049c6_0.app.frontendobjectsissue_toc.tpl.php(168): Smarty_Internal_Template->_subTemplateRender('app:frontend/ob...', NULL, 'e26d2de61022674...', 0, 3600, Array, 0, true) #6 /var/www/html/lib/pkp/lib/vendor/smarty/smarty/libs/sysplugins/smarty_template_resource_base.php(123): content_68e7b9d1bbfe78_80050193(Object(Smarty_Internal_Template)) #7 /var/www/html/lib/pkp/lib/vendor/smarty/smarty/libs/sysplugins/smarty_template_compiled.php(114): Smarty_Template_Resource_Base->getRenderedTemplateCode(Object(Smarty_Internal_Template)) #8 /var/www/html/lib/pkp/lib/vendor/smarty/smarty/libs/sysplugins/smarty_internal_template.php(217): Smarty_Template_Compiled->render(Object(Smarty_Internal_Template)) #9 /var/www/html/lib/pkp/lib/vendor/smarty/smarty/libs/sysplugins/smarty_internal_template.php(386): Smarty_Internal_Template->render() #10 /var/www/html/cache/t_compile/e26d2de610226743d9feff244fb14ef53700227f^fcbc2cabc0d4dff6219d7e4b5d36c1363533cfd8_0.app.frontendpagesissue.tpl.php(51): Smarty_Internal_Template->_subTemplateRender('app:frontend/ob...', NULL, 'e26d2de61022674...', 0, 3600, Array, 0, false) #11 /var/www/html/lib/pkp/lib/vendor/smarty/smarty/libs/sysplugins/smarty_template_resource_base.php(123): content_68e7b9d1ad1870_31758885(Object(Smarty_Internal_Template)) #12 /var/www/html/lib/pkp/lib/vendor/smarty/smarty/libs/sysplugins/smarty_template_compiled.php(114): Smarty_Template_Resource_Base->getRenderedTemplateCode(Object(Smarty_Internal_Template)) #13 /var/www/html/lib/pkp/lib/vendor/smarty/smarty/libs/sysplugins/smarty_internal_template.php(217): Smarty_Template_Compiled->render(Object(Smarty_Internal_Template)) #14 /var/www/html/lib/pkp/lib/vendor/smarty/smarty/libs/sysplugins/smarty_internal_templatebase.php(238): Smarty_Internal_Template->render(false, 1) #15 /var/www/html/lib/pkp/lib/vendor/smarty/smarty/libs/sysplugins/smarty_internal_templatebase.php(134): Smarty_Internal_TemplateBase->_execute(Object(Smarty_Internal_Template), NULL, 'e26d2de61022674...', NULL, 1) #16 /var/www/html/lib/pkp/classes/template/PKPTemplateManager.inc.php(1250): Smarty_Internal_TemplateBase->display('frontend/pages/...', NULL, 'e26d2de61022674...', NULL) #17 /var/www/html/pages/issue/IssueHandler.inc.php(110): PKPTemplateManager->display('frontend/pages/...') #18 /var/www/html/lib/pkp/classes/core/PKPRouter.inc.php(397): IssueHandler->view(Array, Object(Request)) #19 /var/www/html/lib/pkp/classes/core/PKPPageRouter.inc.php(246): PKPRouter->_authorizeInitializeAndCallRequest(Array, Object(Request), Array, false) #20 /var/www/html/lib/pkp/classes/core/Dispatcher.inc.php(144): PKPPageRouter->route(Object(Request)) #21 /var/www/html/lib/pkp/classes/core/PKPApplication.inc.php(360): Dispatcher->dispatch(Object(Request)) #22 /var/www/html/index.php(68): PKPApplication->execute() #23 {main} thrown in /var/www/html/lib/pkp/classes/publication/PKPPublication.inc.php on line 168