PHP 8.0 fatal errors after upgrading to 3.3.0.13

Dear Team and Community,
I would like to thank all of you for your continues support and your great effort
We had upgraded our system to the newer one
once we have done the upgrade, we got errors in the log file. Below is a selected sample of the errors:
Old OJS was : 3.3.0.11 and PHP is 7.4
Newer One is : 3.3.0.13 and PHP is 8.0
Your help with this important problem is really and highly appreciated,
Regards,

Next Doctrine\DBAL\Driver\PDO\Exception: SQLSTATE[23000]: Integrity constraint violation: 1062 Duplicate entry 'fadaaa1cfeda81efe7b6db8b9df3b28c' for key 'sessions_pkey' in /*********/********************8/public_html/lib/pkp/lib/vendor/doctrine/dbal/lib/Doctrine/DBAL/Driver/PDO/Exception.php:18
Stack trace:
#0 /*********/********************8/public_html/lib/pkp/lib/vendor/doctrine/dbal/lib/Doctrine/DBAL/Driver/PDOStatement.php(117): Doctrine\DBAL\Driver\PDO\Exception::new(Object(PDOException))
#1 /*********/********************8/public_html/lib/pkp/lib/vendor/laravel/framework/src/Illuminate/Database/Connection.php(489): Doctrine\DBAL\Driver\PDOStatement->execute()
#2 /*********/********************8/public_html/lib/pkp/lib/vendor/laravel/framework/src/Illuminate/Database/Connection.php(664): Illuminate\Database\Connection->Illuminate\Database\{closure}('INSERT INTO ses...', Array)
#3 /*********/********************8/public_html/lib/pkp/lib/vendor/laravel/framework/src/Illuminate/Database/Connection.php(631): Illuminate\Database\Connection->runQueryCallback('INSERT INTO ses...', Array, Object(Closure))
#4 /*********/********************8/public_html/lib/pkp/lib/vendor/laravel/framework/src/Illuminate/Database/Connection.php(496): Illuminate\Database\Connection->run('INSERT INTO ses...', Array, Object(Closure))
#5 /*********/********************8/public_html/lib/pkp/lib/vendor/laravel/framework/src/Illuminate/Database/Capsule/Manager.php(200): Illuminate\Database\Connection->affectingStatement('INSERT INTO ses...', Array)
#6 /*********/********************8/public_html/lib/pkp/classes/db/DAO.inc.php(138): Illuminate\Database\Capsule\Manager::__callStatic('affectingStatem...', Array)
#7 /*********/********************8/public_html/lib/pkp/classes/session/SessionDAO.inc.php(72): DAO->update('INSERT INTO ses...', Array)
#8 /*********/********************8/public_html/lib/pkp/classes/session/SessionManager.inc.php(89): SessionDAO->insertObject(Object(Session))
#9 /*********/********************8/public_html/lib/pkp/classes/session/SessionManager.inc.php(129): SessionManager->__construct(Object(SessionDAO), Object(Request))
#10 /*********/********************8/public_html/lib/pkp/classes/i18n/PKPLocale.inc.php(131): SessionManager::getManager()
#11 /*********/********************8/public_html/lib/pkp/classes/i18n/PKPLocale.inc.php(290): PKPLocale::getLocale()
#12 /*********/********************8/public_html/lib/pkp/classes/core/Dispatcher.inc.php(116): PKPLocale::initialize(Object(Request))
#13 /*********/********************8/public_html/lib/pkp/classes/core/PKPApplication.inc.php(362): Dispatcher->dispatch(Object(Request))
#14 /*********/********************8/public_html/index.php(68): PKPApplication->execute()
#15 {main}

Next Illuminate\Database\QueryException: SQLSTATE[23000]: Integrity constraint violation: 1062 Duplicate entry 'fadaaa1cfeda81efe7b6db8b9df3b28c' for key 'sessions_pkey' (SQL: INSERT INTO sessions
				(session_id, ip_address, user_agent, created, last_used, remember, data, domain)
				VALUES
				(fadaaa1cfeda81efe7b6db8b9df3b28c, 37.236.238.31, Mozilla/5.0 (Windows NT 10.0; Win64; x64) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/105.0.0.0 Safari/537.36, 1665727202, 1665727202, 0, , journal.uokufa.edu.iq)) in /*********/********************8/public_html/lib/pkp/lib/vendor/laravel/framework/src/Illuminate/Database/Connection.php:671
Stack trace:
#0 /*********/********************8/public_html/lib/pkp/lib/vendor/laravel/framework/src/Illuminate/Database/Connection.php(631): Illuminate\Database\Connection->runQueryCallback('INSERT INTO ses...', Array, Object(Closure))
#1 /*********/********************8/public_html/lib/pkp/lib/vendor/laravel/framework/src/Illuminate/Database/Connection.php(496): Illuminate\Database\Connection->run('INSERT INTO ses...', Array, Object(Closure))
#2 /*********/********************8/public_html/lib/pkp/lib/vendor/laravel/framework/src/Illuminate/Database/Capsule/Manager.php(200): Illuminate\Database\Connection->affectingStatement('INSERT INTO ses...', Array)
#3 /*********/********************8/public_html/lib/pkp/classes/db/DAO.inc.php(138): Illuminate\Database\Capsule\Manager::__callStatic('affectingStatem...', Array)
#4 /*********/********************8/public_html/lib/pkp/classes/session/SessionDAO.inc.php(72): DAO->update('INSERT INTO ses...', Array)
#5 /*********/********************8/public_html/lib/pkp/classes/session/SessionManager.inc.php(89): SessionDAO->insertObject(Object(Session))
#6 /*********/********************8/public_html/lib/pkp/classes/session/SessionManager.inc.php(129): SessionManager->__construct(Object(SessionDAO), Object(Request))
#7 /*********/********************8/public_html/lib/pkp/classes/i18n/PKPLocale.inc.php(131): SessionManager::getManager()
#8 /*********/********************8/public_html/lib/pkp/classes/i18n/PKPLocale.inc.php(290): PKPLocale::getLocale()
#9 /*********/********************8/public_html/lib/pkp/classes/core/Dispatcher.inc.php(116): PKPLocale::initialize(Object(Request))
#10 /*********/********************8/public_html/lib/pkp/classes/core/PKPApplication.inc.php(362): Dispatcher->dispatch(Object(Request))
#11 /*********/********************8/public_html/index.php(68): PKPApplication->execute()
#12 {main}
  thrown in /*********/********************8/public_html/lib/pkp/lib/vendor/laravel/framework/src/Illuminate/Database/Connection.php on line 671
[14-Oct-2022 09:03:34 Asia/Baghdad] PHP Warning:  Attempt to read property "single" on null in /*********/********************8/public_html/plugins/generic/citationStyleLanguage/lib/vendor/seboettg/citeproc-php/src/Rendering/Date/DatePart.php on line 227
[14-Oct-2022 09:06:42 Asia/Baghdad] PHP Warning:  Attempt to read property "single" on null in /*********/********************8/public_html/plugins/generic/citationStyleLanguage/lib/vendor/seboettg/citeproc-php/src/Rendering/Date/DatePart.php on line 227
[14-Oct-2022 09:11:14 Asia/Baghdad] PHP Warning:  Attempt to read property "single" on null in /*********/********************8/public_html/plugins/generic/citationStyleLanguage/lib/vendor/seboettg/citeproc-php/src/Rendering/Date/DatePart.php on line 227
[14-Oct-2022 09:11:29 Asia/Baghdad] PHP Warning:  Attempt to read property "single" on null in /*********/********************8/public_html/plugins/generic/citationStyleLanguage/lib/vendor/seboettg/citeproc-php/src/Rendering/Date/DatePart.php on line 227
[14-Oct-2022 09:17:10 Asia/Baghdad] PHP Warning:  Attempt to read property "single" on null in /*********/********************8/public_html/plugins/generic/citationStyleLanguage/lib/vendor/seboettg/citeproc-php/src/Rendering/Date/DatePart.php on line 227
[14-Oct-2022 09:18:17 Asia/Baghdad] PHP Warning:  Attempt to read property "single" on null in /*********/********************8/public_html/plugins/generic/citationStyleLanguage/lib/vendor/seboettg/citeproc-php/src/Rendering/Date/DatePart.php on line 227
[14-Oct-2022 09:20:10 Asia/Baghdad] PHP Warning:  Attempt to read property "single" on null in /*********/********************8/public_html/plugins/generic/citationStyleLanguage/lib/vendor/seboettg/citeproc-php/src/Rendering/Date/DatePart.php on line 227
[14-Oct-2022 09:20:34 Asia/Baghdad] PHP Warning:  Attempt to read property "single" on null in /*********/********************8/public_html/plugins/generic/citationStyleLanguage/lib/vendor/seboettg/citeproc-php/src/Rendering/Date/DatePart.php on line 227
[14-Oct-2022 09:22:46 Asia/Baghdad] PHP Warning:  Attempt to read property "single" on null in /*********/********************8/public_html/plugins/generic/citationStyleLanguage/lib/vendor/seboettg/citeproc-php/src/Rendering/Date/DatePart.php on line 227
[14-Oct-2022 09:25:07 Asia/Baghdad] PHP Warning:  Trying to access array offset on value of type null in /*********/********************8/public_html/plugins/themes/default/DefaultThemePlugin.inc.php on line 163
[14-Oct-2022 09:25:48 Asia/Baghdad] PHP Warning:  Trying to access array offset on value of type null in /*********/********************8/public_html/plugins/themes/default/DefaultThemePlugin.inc.php on line 163
[14-Oct-2022 09:27:41 Asia/Baghdad] PHP Warning:  Trying to access array offset on value of type null in /*********/********************8/public_html/plugins/themes/default/DefaultThemePlugin.inc.php on line 163
[14-Oct-2022 09:28:13 Asia/Baghdad] PHP Warning:  Trying to access array offset on value of type null in /*********/********************8/public_html/plugins/themes/default/DefaultThemePlugin.inc.php on line 163
[14-Oct-2022 09:28:48 Asia/Baghdad] PHP Warning:  Trying to access array offset on value of type null in /*********/********************8/public_html/plugins/themes/default/DefaultThemePlugin.inc.php on line 163
[14-Oct-2022 09:28:59 Asia/Baghdad] PHP Warning:  Trying to access array offset on value of type null in /*********/********************8/public_html/plugins/themes/default/DefaultThemePlugin.inc.php on line 163
[14-Oct-2022 13:50:57 Asia/Baghdad] PHP Fatal error:  Uncaught Error: Non-static method AccessKeyManager::generateKeyHash() cannot be called statically in /*********/********************8/public_html/pages/reviewer/ReviewerHandler.inc.php:78
Stack trace:
#0 /*********/********************8/public_html/pages/reviewer/ReviewerHandler.inc.php(38): ReviewerHandler->_validateAccessKey(Object(Request))
#1 /*********/********************8/public_html/lib/pkp/classes/core/PKPRouter.inc.php(387): ReviewerHandler->authorize(Object(Request), Array, Array)
#2 /*********/********************8/public_html/lib/pkp/classes/core/PKPPageRouter.inc.php(246): PKPRouter->_authorizeInitializeAndCallRequest(Array, Object(Request), Array, false)
#3 /*********/********************8/public_html/lib/pkp/classes/core/Dispatcher.inc.php(144): PKPPageRouter->route(Object(Request))
#4 /*********/********************8/public_html/lib/pkp/classes/core/PKPApplication.inc.php(362): Dispatcher->dispatch(Object(Request))
#5 /*********/********************8/public_html/index.php(68): PKPApplication->execute()
#6 {main}
  thrown in /*********/********************8/public_html/pages/reviewer/ReviewerHandler.inc.php on line 78
[14-Oct-2022 13:51:02 Asia/Baghdad] PHP Fatal error:  Uncaught Error: Non-static method AccessKeyManager::generateKeyHash() cannot be called statically in /*********/********************8/public_html/pages/reviewer/ReviewerHandler.inc.php:78
Stack trace:
#0 /*********/********************8/public_html/pages/reviewer/ReviewerHandler.inc.php(38): ReviewerHandler->_validateAccessKey(Object(Request))
#1 /*********/********************8/public_html/lib/pkp/classes/core/PKPRouter.inc.php(387): ReviewerHandler->authorize(Object(Request), Array, Array)
#2 /*********/********************8/public_html/lib/pkp/classes/core/PKPPageRouter.inc.php(246): PKPRouter->_authorizeInitializeAndCallRequest(Array, Object(Request), Array, false)
#3 /*********/********************8/public_html/lib/pkp/classes/core/Dispatcher.inc.php(144): PKPPageRouter->route(Object(Request))
#4 /*********/********************8/public_html/lib/pkp/classes/core/PKPApplication.inc.php(362): Dispatcher->dispatch(Object(Request))
#5 /*********/********************8/public_html/index.php(68): PKPApplication->execute()
#6 {main}
  thrown in /*********/********************8/public_html/pages/reviewer/ReviewerHandler.inc.php on line 78
[14-Oct-2022 22:11:12 Asia/Baghdad] PHP Fatal error:  Uncaught TypeError: count(): Argument #1 ($value) must be of type Countable|array, null given in /*********/********************8/public_html/cache/t_compile/f3f61f20c8cf263a6a0dca9d99469f9f95568d26^4ef1996850f75e89a53007d1a8243f48d8f4148f_0.app.submissionformcategories..php:24
Stack trace:
#0 /*********/********************8/public_html/lib/pkp/lib/vendor/smarty/smarty/libs/sysplugins/smarty_template_resource_base.php(123): content_6348f1eb7c8bf4_12084488(Object(Smarty_Internal_Template))
#1 /*********/********************8/public_html/lib/pkp/lib/vendor/smarty/smarty/libs/sysplugins/smarty_template_compiled.php(114): Smarty_Template_Resource_Base->getRenderedTemplateCode(Object(Smarty_Internal_Template))
#2 /*********/********************8/public_html/lib/pkp/lib/vendor/smarty/smarty/libs/sysplugins/smarty_internal_template.php(216): Smarty_Template_Compiled->render(Object(Smarty_Internal_Template))
#3 /*********/********************8/public_html/lib/pkp/lib/vendor/smarty/smarty/libs/sysplugins/smarty_internal_template.php(385): Smarty_Internal_Template->render()
#4 /*********/********************8/public_html/cache/t_compile/f3f61f20c8cf263a6a0dca9d99469f9f95568d26^c7d6d017cda209d97dfa69aba1e0226666e0255e_0.core.submissionformstep1.tpl.php(66): Smarty_Internal_Template->_subTemplateRender('app:submission/...', NULL, 'f3f61f20c8cf263...', 0, 3600, Array, 0, false)
#5 /*********/********************8/public_html/lib/pkp/lib/vendor/smarty/smarty/libs/sysplugins/smarty_template_resource_base.php(123): content_6348f1eb7b0a62_52917791(Object(Smarty_Internal_Template))
#6 /*********/********************8/public_html/lib/pkp/lib/vendor/smarty/smarty/libs/sysplugins/smarty_template_compiled.php(114): Smarty_Template_Resource_Base->getRenderedTemplateCode(Object(Smarty_Internal_Template))
#7 /*********/********************8/public_html/lib/pkp/lib/vendor/smarty/smarty/libs/sysplugins/smarty_internal_template.php(216): Smarty_Template_Compiled->render(Object(Smarty_Internal_Template))
#8 /*********/********************8/public_html/lib/pkp/lib/vendor/smarty/smarty/libs/sysplugins/smarty_internal_template.php(385): Smarty_Internal_Template->render()
#9 /*********/********************8/public_html/cache/t_compile/f3f61f20c8cf263a6a0dca9d99469f9f95568d26^d4a7db69d40565910b7236a1c96ad325268f4ab6_0.app.submissionformstep1.tpl.php(52): Smarty_Internal_Template->_subTemplateRender('core:submission...', NULL, 'f3f61f20c8cf263...', 0, 3600, Array, 0, false)
#10 /*********/********************8/public_html/lib/pkp/lib/vendor/smarty/smarty/libs/sysplugins/smarty_template_resource_base.php(123): content_6348f1eb76d081_70469952(Object(Smarty_Internal_Template))
#11 /*********/********************8/public_html/lib/pkp/lib/vendor/smarty/smarty/libs/sysplugins/smarty_template_compiled.php(114): Smarty_Template_Resource_Base->getRenderedTemplateCode(Object(Smarty_Internal_Template))
#12 /*********/********************8/public_html/lib/pkp/lib/vendor/smarty/smarty/libs/sysplugins/smarty_internal_template.php(216): Smarty_Template_Compiled->render(Object(Smarty_Internal_Template))
#13 /*********/********************8/public_html/lib/pkp/lib/vendor/smarty/smarty/libs/sysplugins/smarty_internal_templatebase.php(232): Smarty_Internal_Template->render(false, 0)
#14 /*********/********************8/public_html/lib/pkp/lib/vendor/smarty/smarty/libs/sysplugins/smarty_internal_templatebase.php(116): Smarty_Internal_TemplateBase->_execute(Object(Smarty_Internal_Template), NULL, 'f3f61f20c8cf263...', NULL, 0)
#15 /*********/********************8/public_html/lib/pkp/classes/template/PKPTemplateManager.inc.php(1072): Smarty_Internal_TemplateBase->fetch('submission/form...', NULL, 'f3f61f20c8cf263...', NULL)
#16 /*********/********************8/public_html/lib/pkp/classes/form/Form.inc.php(197): PKPTemplateManager->fetch('submission/form...')
#17 /*********/********************8/public_html/lib/pkp/classes/submission/form/SubmissionSubmitForm.inc.php(69): Form->fetch(Object(Request), NULL, false)
#18 /*********/********************8/public_html/lib/pkp/classes/submission/form/PKPSubmissionSubmitStep1Form.inc.php(179): SubmissionSubmitForm->fetch(Object(Request), NULL, false)
#19 /*********/********************8/public_html/classes/submission/form/SubmissionSubmitStep1Form.inc.php(63): PKPSubmissionSubmitStep1Form->fetch(Object(Request), NULL, false)
#20 /*********/********************8/public_html/lib/pkp/pages/submission/PKPSubmissionHandler.inc.php(198): SubmissionSubmitStep1Form->fetch(Object(Request))
#21 /*********/********************8/public_html/lib/pkp/classes/core/PKPRouter.inc.php(395): PKPSubmissionHandler->saveStep(Array, Object(Request))
#22 /*********/********************8/public_html/lib/pkp/classes/core/PKPPageRouter.inc.php(246): PKPRouter->_authorizeInitializeAndCallRequest(Array, Object(Request), Array, false)
#23 /*********/********************8/public_html/lib/pkp/classes/core/Dispatcher.inc.php(144): PKPPageRouter->route(Object(Request))
#24 /*********/********************8/public_html/lib/pkp/classes/core/PKPApplication.inc.php(362): Dispatcher->dispatch(Object(Request))
#25 /*********/********************8/public_html/index.php(68): PKPApplication->execute()
#26 {main}
  thrown in /*********/********************8/public_html/cache/t_compile/f3f61f20c8cf263a6a0dca9d99469f9f95568d26^4ef1996850f75e89a53007d1a8243f48d8f4148f_0.app.submissionformcategories..php on line 24
[14-Oct-2022 22:11:53 Asia/Baghdad] ojs2: 404 Not Found
[14-Oct-2022 22:11:53 Asia/Baghdad] PHP Warning:  Trying to access array offset on value of type null in /*********/********************8/public_html/plugins/themes/default/DefaultThemePlugin.inc.php on line 163
[14-Oct-2022 22:17:10 Asia/Baghdad] PHP Warning:  Trying to access array offset on value of type null in /*********/********************8/public_html/plugins/themes/default/DefaultThemePlugin.inc.php on line 163
[14-Oct-2022 22:17:11 Asia/Baghdad] PHP Warning:  Trying to access array offset on value of type null in /*********/********************8/public_html/plugins/themes/default/DefaultThemePlugin.inc.php on line 163
[14-Oct-2022 22:17:12 Asia/Baghdad] PHP Warning:  Trying to access array offset on value of type null in /*********/********************8/public_html/plugins/themes/default/DefaultThemePlugin.inc.php on line 163
[14-Oct-2022 22:17:47 Asia/Baghdad] PHP Warning:  Trying to access array offset on value of type null in /*********/********************8/public_html/plugins/themes/default/DefaultThemePlugin.inc.php on line 163
[14-Oct-2022 22:17:57 Asia/Baghdad] ojs2: 404 Not Found
[14-Oct-2022 22:18:55 Asia/Baghdad] ojs2: 404 Not Found
[14-Oct-2022 22:19:54 Asia/Baghdad] ojs2: 404 Not Found
[14-Oct-2022 22:20:38 Asia/Baghdad] PHP Warning:  Trying to access array offset on value of type null in /*********/********************8/public_html/plugins/themes/default/DefaultThemePlugin.inc.php on line 163
[14-Oct-2022 22:20:50 Asia/Baghdad] PHP Warning:  Trying to access array offset on value of type null in /*********/********************8/public_html/plugins/themes/default/DefaultThemePlugin.inc.php on line 163
[14-Oct-2022 22:21:40 Asia/Baghdad] ojs2: 404 Not Found
[14-Oct-2022 22:31:54 Asia/Baghdad] PHP Warning:  Trying to access array offset on value of type null in /*********/********************8/public_html/plugins/themes/default/DefaultThemePlugin.inc.php on line 163
[14-Oct-2022 22:31:55 Asia/Baghdad] PHP Warning:  Trying to access array offset on value of type null in /*********/********************8/public_html/plugins/themes/default/DefaultThemePlugin.inc.php on line 163
[14-Oct-2022 22:31:56 Asia/Baghdad] ojs2: 404 Not Found
[14-Oct-2022 22:32:33 Asia/Baghdad] PHP Warning:  Trying to access array offset on value of type null in /*********/********************8/public_html/plugins/themes/default/DefaultThemePlugin.inc.php on line 163
[14-Oct-2022 22:36:03 Asia/Baghdad] PHP Warning:  Trying to access array offset on value of type null in /*********/********************8/public_html/plugins/themes/default/DefaultThemePlugin.inc.php on line 163
[14-Oct-2022 22:36:13 Asia/Baghdad] PHP Warning:  Trying to access array offset on value of type null in /*********/********************8/public_html/plugins/themes/default/DefaultThemePlugin.inc.php on line 163
[14-Oct-2022 22:37:19 Asia/Baghdad] PHP Warning:  Trying to access array offset on value of type null in /*********/********************8/public_html/plugins/themes/default/DefaultThemePlugin.inc.php on line 163
[14-Oct-2022 22:37:35 Asia/Baghdad] PHP Warning:  Trying to access array offset on value of type null in /*********/********************8/public_html/plugins/themes/default/DefaultThemePlugin.inc.php on line 163
[14-Oct-2022 22:39:13 Asia/Baghdad] PHP Warning:  Trying to access array offset on value of type null in /*********/********************8/public_html/plugins/themes/default/DefaultThemePlugin.inc.php on line 163
[14-Oct-2022 22:39:13 Asia/Baghdad] ojs2: 404 Not Found

Thank you in advance

Hey @asmecher,
Could you please take a look at the error logs above. your help is highly appreciated
Thank you

Hi @Salam_Al-Khammasi

Have you tried to clear out your sessions table from data? It might be possible that your upgrade process via CLI has created a session which is duplicated when you attempt to access the upgraded version for the first time.

Please, make a backup of your DB before any change to it. If something goes wrong you will be able to restore it.

Best,
Israel

1 Like

Thanks a lot @israel.cefrin
That’s really solve the problem!
Really appreciate your time to reply
-Salam

However, I’m still getting these warnings they keep appear frequently. Any idea why I’m getting this

[14-Oct-2022 09:03:34 Asia/Baghdad] PHP Warning:  Attempt to read property "single" on null in /*********/********************8/public_html/plugins/generic/citationStyleLanguage/lib/vendor/seboettg/citeproc-php/src/Rendering/Date/DatePart.php on line 227
[14-Oct-2022 09:06:42 Asia/Baghdad] PHP Warning:  Attempt to read property "single" on null in /*********/********************8/public_html/plugins/generic/citationStyleLanguage/lib/vendor/seboettg/citeproc-php/src/Rendering/Date/DatePart.php on line 227
[14-Oct-2022 09:11:14 Asia/Baghdad] PHP Warning:  Attempt to read property "single" on null in /*********/********************8/public_html/plugins/generic/citationStyleLanguage/lib/vendor/seboettg/citeproc-php/src/Rendering/Date/DatePart.php on line 227
[14-Oct-2022 09:11:29 Asia/Baghdad] PHP Warning:  Attempt to read property "single" on null in /*********/********************8/public_html/plugins/generic/citationStyleLanguage/lib/vendor/seboettg/citeproc-php/src/Rendering/Date/DatePart.php on line 227
[14-Oct-2022 09:17:10 Asia/Baghdad] PHP Warning:  Attempt to read property "single" on null in /*********/********************8/public_html/plugins/generic/citationStyleLanguage/lib/vendor/seboettg/citeproc-php/src/Rendering/Date/DatePart.php on line 227
[14-Oct-2022 09:18:17 Asia/Baghdad] PHP Warning:  Attempt to read property "single" on null in /*********/********************8/public_html/plugins/generic/citationStyleLanguage/lib/vendor/seboettg/citeproc-php/src/Rendering/Date/DatePart.php on line 227
[14-Oct-2022 09:20:10 Asia/Baghdad] PHP Warning:  Attempt to read property "single" on null in /*********/********************8/public_html/plugins/generic/citationStyleLanguage/lib/vendor/seboettg/citeproc-php/src/Rendering/Date/DatePart.php on line 227
[14-Oct-2022 09:20:34 Asia/Baghdad] PHP Warning:  Attempt to read property "single" on null in /*********/********************8/public_html/plugins/generic/citationStyleLanguage/lib/vendor/seboettg/citeproc-php/src/Rendering/Date/DatePart.php on line 227
[14-Oct-2022 09:22:46 Asia/Baghdad] PHP Warning:  Attempt to read property "single" on null in /*********/********************8/public_html/plugins/generic/citationStyleLanguage/lib/vendor/seboettg/citeproc-php/src/Rendering/Date/DatePart.php on line 227