Need help please with a php fatal error when using the quicksubmit plugin

After using it without issues for years, I’ve recently updated OJS (from 2.2 to 2.4 I think) because our server migrated to php7 and the code stopped working. I hope I did the upgrade well but I am not a specialist. Now I try to use the quicksubmit plugin, but it freezes. In my php error log, I have a series of warning (from what I’ve read they are cosmetic) and a php fatal error :

[30-Jan-2020 06:38:05 UTC] PHP Fatal error: Uncaught Error: Using $this when not in object context in /home/enthaeuc/public_html/classes/author/form/submit/AuthorSubmitForm.inc.php:109
Stack trace:
#0 /home/enthaeuc/public_html/plugins/importexport/quickSubmit/QuickSubmitForm.inc.php(409): AuthorSubmitForm::assignEditors(Object(Article))
#1 /home/enthaeuc/public_html/plugins/importexport/quickSubmit/QuickSubmitPlugin.inc.php(140): QuickSubmitForm->execute()
#2 /home/enthaeuc/public_html/plugins/importexport/quickSubmit/QuickSubmitPlugin.inc.php(57): QuickSubmitPlugin->saveSubmit(Array, Object(Request))
#3 /home/enthaeuc/public_html/pages/manager/ImportExportHandler.inc.php(43): QuickSubmitPlugin->display(Array, Object(Request))
#4 /home/enthaeuc/public_html/lib/pkp/classes/core/PKPRouter.inc.php(362): ImportExportHandler->importexport(Array, Object(Request))
#5 /home/enthaeuc/public_html/lib/pkp/classes/core/PKPPageRouter.inc.php(220): PKPRouter->_authorizeInitializeAndCallRequest(Array, Object(Request), Array, false)
#6 /home/enthaeuc/public_html/lib/ in /home/enthaeuc/public_html/classes/author/form/submit/AuthorSubmitForm.inc.php on line 109

  • Application Version - OJS 2.4.8.4