Users Having difficulty submitting article

I have a journal system running on OJS 3.3.0.13 we have publish some issues and we are currently accepting articles for our next publication, we have about 40 submitted articles but all of a sudden the journal systems refuses to complete submissions, it get stocked on the meta data stage, i have tried to clean up my data base by deleting all incomplete submission but all proof not to solve the problem on my error log this is what i saw:

[12-Jun-2023 01:30:02 Africa/Lagos] ojs2: 404 Not Found
[12-Jun-2023 02:54:54 Africa/Lagos] Server host "www.wnjms.com.ng not allowed!
[12-Jun-2023 02:54:54 Africa/Lagos] ojs2: 400 Bad Request
[12-Jun-2023 04:38:30 Africa/Lagos] Server host "www.wnjms.com.ng not allowed!
[12-Jun-2023 04:38:31 Africa/Lagos] ojs2: 400 Bad Request
[12-Jun-2023 05:23:03 Africa/Lagos] Server host "www.wnjms.com.ng not allowed!
[12-Jun-2023 05:23:03 Africa/Lagos] ojs2: 400 Bad Request
[12-Jun-2023 06:47:33 Africa/Lagos] PHP Fatal error: Uncaught Error: Call to a member function getFullName() on null in /home/wnjmscom/public_html/journal/lib/pkp/classes/submission/reviewAssignment/ReviewAssignmentDAO.inc.php:453
Stack trace:
#0 /home/wnjmscom/public_html/journal/lib/pkp/classes/submission/reviewAssignment/ReviewAssignmentDAO.inc.php(139): ReviewAssignmentDAO->_fromRow(Array)
#1 /home/wnjmscom/public_html/journal/lib/pkp/classes/task/ReviewReminder.inc.php(133): ReviewAssignmentDAO->getIncompleteReviewAssignments()
#2 /home/wnjmscom/public_html/journal/lib/pkp/classes/scheduledTask/ScheduledTask.inc.php(146): ReviewReminder->executeActions()
#3 /home/wnjmscom/public_html/journal/lib/pkp/plugins/generic/acron/PKPAcronPlugin.inc.php(258): ScheduledTask->execute()
#4 [internal function]: PKPAcronPlugin->shutdownFunction()
#5 {main}
thrown in /home/wnjmscom/public_html/journal/lib/pkp/classes/submission/reviewAssignment/ReviewAssignmentDAO.inc.php on line 453
[12-Jun-2023 13:32:41 Africa/Lagos] PHP Warning: Undefined array key “certification” in /home/wnjmscom/public_html/journal/lib/pkp/classes/plugins/PluginGalleryDAO.inc.php on line 194
[12-Jun-2023 13:32:41 Africa/Lagos] PHP Warning: Undefined array key “certification” in /home/wnjmscom/public_html/journal/lib/pkp/classes/plugins/PluginGalleryDAO.inc.php on line 194
[12-Jun-2023 13:32:41 Africa/Lagos] PHP Warning: Undefined array key “certification” in /home/wnjmscom/public_html/journal/lib/pkp/classes/plugins/PluginGalleryDAO.inc.php on line 194
[13-Jun-2023 07:03:19 Africa/Lagos] PHP Fatal error: Uncaught Error: Call to a member function getFullName() on null in /home/wnjmscom/public_html/journal/lib/pkp/classes/submission/reviewAssignment/ReviewAssignmentDAO.inc.php:453
Stack trace:
#0 /home/wnjmscom/public_html/journal/lib/pkp/classes/submission/reviewAssignment/ReviewAssignmentDAO.inc.php(139): ReviewAssignmentDAO->_fromRow(Array)
#1 /home/wnjmscom/public_html/journal/lib/pkp/classes/task/ReviewReminder.inc.php(133): ReviewAssignmentDAO->getIncompleteReviewAssignments()
#2 /home/wnjmscom/public_html/journal/lib/pkp/classes/scheduledTask/ScheduledTask.inc.php(146): ReviewReminder->executeActions()
#3 /home/wnjmscom/public_html/journal/lib/pkp/plugins/generic/acron/PKPAcronPlugin.inc.php(258): ScheduledTask->execute()
#4 [internal function]: PKPAcronPlugin->shutdownFunction()
#5 {main}
thrown in /home/wnjmscom/public_html/journal/lib/pkp/classes/submission/reviewAssignment/ReviewAssignmentDAO.inc.php on line 453
[13-Jun-2023 12:37:06 Africa/Lagos] PHP Warning: Undefined array key “certification” in /home/wnjmscom/public_html/journal/lib/pkp/classes/plugins/PluginGalleryDAO.inc.php on line 194
[13-Jun-2023 12:37:06 Africa/Lagos] PHP Warning: Undefined array key “certification” in /home/wnjmscom/public_html/journal/lib/pkp/classes/plugins/PluginGalleryDAO.inc.php on line 194
[13-Jun-2023 12:37:06 Africa/Lagos] PHP Warning: Undefined array key “certification” in /home/wnjmscom/public_html/journal/lib/pkp/classes/plugins/PluginGalleryDAO.inc.php on line 194
[13-Jun-2023 13:23:22 Africa/Lagos] PHP Fatal error: Uncaught TypeError: count(): Argument #1 ($value) must be of type Countable|array, null given in /home/wnjmscom/public_html/journal/cache/t_compile/cfac7d723fa83a8468f3fec3577c93a53cdab919^4ef1996850f75e89a53007d1a8243f48d8f4148f_0.app.submissionformcategories…php:24
Stack trace:
#0 /home/wnjmscom/public_html/journal/lib/pkp/lib/vendor/smarty/smarty/libs/sysplugins/smarty_template_resource_base.php(123): content_639aca76826cb1_75897425(Object(Smarty_Internal_Template))
#1 /home/wnjmscom/public_html/journal/lib/pkp/lib/vendor/smarty/smarty/libs/sysplugins/smarty_template_compiled.php(114): Smarty_Template_Resource_Base->getRenderedTemplateCode(Object(Smarty_Internal_Template))
#2 /home/wnjmscom/public_html/journal/lib/pkp/lib/vendor/smarty/smarty/libs/sysplugins/smarty_internal_template.php(216): Smarty_Template_Compiled->render(Object(Smarty_Internal_Template))
#3 /home/wnjmscom/public_html/journal/lib/pkp/lib/vendor/smarty/smarty/libs/sysplugins/smarty_internal_template.php(385): Smarty_Internal_Template->render()
#4 /home/wnjmscom/public_html/journal/cache/t_compile/cfac7d723fa83a8468f3fec3577c93a53cdab919^c7d6d017cda209d97dfa69aba1e0226666e0255e_0.core.submissionformstep1.tpl.php(66): Smarty_Internal_Template->_subTemplateRender(‘app:submission/…’, NULL, ‘cfac7d723fa83a8…’, 0, 3600, Array, 0, false)
#5 /home/wnjmscom/public_html/journal/lib/pkp/lib/vendor/smarty/smarty/libs/sysplugins/smarty_template_resource_base.php(123): content_639aca76709ae3_17457538(Object(Smarty_Internal_Template))
#6 /home/wnjmscom/public_html/journal/lib/pkp/lib/vendor/smarty/smarty/libs/sysplugins/smarty_template_compiled.php(114): Smarty_Template_Resource_Base->getRenderedTemplateCode(Object(Smarty_Internal_Template))
#7 /home/wnjmscom/public_html/journal/lib/pkp/lib/vendor/smarty/smarty/libs/sysplugins/smarty_internal_template.php(216): Smarty_Template_Compiled->render(Object(Smarty_Internal_Template))
#8 /home/wnjmscom/public_html/journal/lib/pkp/lib/vendor/smarty/smarty/libs/sysplugins/smarty_internal_template.php(385): Smarty_Internal_Template->render()
#9 /home/wnjmscom/public_html/journal/cache/t_compile/cfac7d723fa83a8468f3fec3577c93a53cdab919^d4a7db69d40565910b7236a1c96ad325268f4ab6_0.app.submissionformstep1.tpl.php(52): Smarty_Internal_Template->_subTemplateRender(‘core:submission…’, NULL, ‘cfac7d723fa83a8…’, 0, 3600, Array, 0, false)
#10 /home/wnjmscom/public_html/journal/lib/pkp/lib/vendor/smarty/smarty/libs/sysplugins/smarty_template_resource_base.php(123): content_639aca76240d43_39951974(Object(Smarty_Internal_Template))
#11 /home/wnjmscom/public_html/journal/lib/pkp/lib/vendor/smarty/smarty/libs/sysplugins/smarty_template_compiled.php(114): Smarty_Template_Resource_Base->getRenderedTemplateCode(Object(Smarty_Internal_Template))
#12 /home/wnjmscom/public_html/journal/lib/pkp/lib/vendor/smarty/smarty/libs/sysplugins/smarty_internal_template.php(216): Smarty_Template_Compiled->render(Object(Smarty_Internal_Template))
#13 /home/wnjmscom/public_html/journal/lib/pkp/lib/vendor/smarty/smarty/libs/sysplugins/smarty_internal_templatebase.php(232): Smarty_Internal_Template->render(false, 0)
#14 /home/wnjmscom/public_html/journal/lib/pkp/lib/vendor/smarty/smarty/libs/sysplugins/smarty_internal_templatebase.php(116): Smarty_Internal_TemplateBase->_execute(Object(Smarty_Internal_Template), NULL, ‘cfac7d723fa83a8…’, NULL, 0)
#15 /home/wnjmscom/public_html/journal/lib/pkp/classes/template/PKPTemplateManager.inc.php(1072): Smarty_Internal_TemplateBase->fetch(‘submission/form…’, NULL, ‘cfac7d723fa83a8…’, NULL)
#16 /home/wnjmscom/public_html/journal/lib/pkp/classes/form/Form.inc.php(197): PKPTemplateManager->fetch(‘submission/form…’)
#17 /home/wnjmscom/public_html/journal/lib/pkp/classes/submission/form/SubmissionSubmitForm.inc.php(69): Form->fetch(Object(Request), NULL, false)
#18 /home/wnjmscom/public_html/journal/lib/pkp/classes/submission/form/PKPSubmissionSubmitStep1Form.inc.php(179): SubmissionSubmitForm->fetch(Object(Request), NULL, false)
#19 /home/wnjmscom/public_html/journal/classes/submission/form/SubmissionSubmitStep1Form.inc.php(63): PKPSubmissionSubmitStep1Form->fetch(Object(Request), NULL, false)
#20 /home/wnjmscom/public_html/journal/lib/pkp/pages/submission/PKPSubmissionHandler.inc.php(198): SubmissionSubmitStep1Form->fetch(Object(Request))
#21 /home/wnjmscom/public_html/journal/lib/pkp/classes/core/PKPRouter.inc.php(395): PKPSubmissionHandler->saveStep(Array, Object(Request))
#22 /home/wnjmscom/public_html/journal/lib/pkp/classes/core/PKPPageRouter.inc.php(246): PKPRouter->_authorizeInitializeAndCallRequest(Array, Object(Request), Array, false)
#23 /home/wnjmscom/public_html/journal/lib/pkp/classes/core/Dispatcher.inc.php(144): PKPPageRouter->route(Object(Request))
#24 /home/wnjmscom/public_html/journal/lib/pkp/classes/core/PKPApplication.inc.php(362): Dispatcher->dispatch(Object(Request))
#25 /home/wnjmscom/public_html/journal/index.php(68): PKPApplication->execute()
#26 {main}
thrown in /home/wnjmscom/public_html/journal/cache/t_compile/cfac7d723fa83a8468f3fec3577c93a53cdab919^4ef1996850f75e89a53007d1a8243f48d8f4148f_0.app.submissionformcategories…php on line 24

please any assistance to solve this will be appriciated