Version 3.3.3 does not work in Joomla! 5 without "Behaviour - Backward Compatibility" enabled

[eddiekonczal]

I am testing Akeeba Engage 3.3.3 in Joomla! 5 (5.0.3). When the "Behaviour - Backward Compatibility" is disabled, I get this error when trying to post a comment:

The application has stopped responding
Please contact the administrator of the site and let them know of this error and what you were doing when this happened.

[nikosdion]

Akeeba Engage itself does work without the compatibility plugin because it is developed and tested on development and testing sites which do not use said plugin. In fact, when I was porting Engage to Joomla! 5 I had to uninstall JCE because back then it wouldn't work without the compatibility plugin, thus hampering my efforts to provide an experience which does not require the compatibility plugin (this has since been addressed in JCE, by the way).

That said, Joomla! always calls all plugins handling content submission (typically in the content, system, action log, and behaviour groups) every time you submit any kind of content, including comments. When a third party plugin requires the compatibility plugin the comment submission fails.

To make sure of that, set Debug Site to Yes and Error Reporting to Development in Joomla's backend, Global Configuration. Repeat the content submission and you will get a PHP stack trace which tells you which plugin causes the problem.

[eddiekonczal]

Thanks for the suggestions. I enabled debugging and maximum error reporting. However, the debug errors do not seem to point to any third party plugin, but to the Joomla! core:

500 Joomla\CMS\Form\Field\EditorField::filter field body calls a deprecated filter class JComponentHelper, the class needs to be namespaced use \Joomla\CMS\Component\ComponentHelper instead or activate the backward compatible plugin.
File <root>/libraries/src/Form/FormField.php Line 1094

Debug information
Exception type: UnexpectedValueException

#0 /mnt/data/vhosts/casite-1457196.cloudaccess.net/httpdocs/libraries/src/Form/Form.php(1047): Joomla\CMS\Form\FormField->filter('

What sayst t...', NULL, Object(Joomla\Registry\Registry))
#1 /mnt/data/vhosts/casite-1457196.cloudaccess.net/httpdocs/libraries/src/Form/Form.php(991): Joomla\CMS\Form\Form->filter(Array, NULL)
#2 /mnt/data/vhosts/casite-1457196.cloudaccess.net/httpdocs/libraries/src/MVC/Model/FormModel.php(219): Joomla\CMS\Form\Form->process(Array, NULL)
#3 /mnt/data/vhosts/casite-1457196.cloudaccess.net/httpdocs/components/com_engage/src/Model/CommentModel.php(141): Joomla\CMS\MVC\Model\FormModel->validate(Object(Joomla\CMS\Form\Form), Array, NULL)
#4 /mnt/data/vhosts/casite-1457196.cloudaccess.net/httpdocs/libraries/src/MVC/Controller/FormController.php(636): Akeeba\Component\Engage\Site\Model\CommentModel->validate(Object(Joomla\CMS\Form\Form), Array)
#5 /mnt/data/vhosts/casite-1457196.cloudaccess.net/httpdocs/administrator/components/com_engage/src/Mixin/ControllerEventsTrait.php(74): Joomla\CMS\MVC\Controller\FormController->save()
#6 /mnt/data/vhosts/casite-1457196.cloudaccess.net/httpdocs/libraries/src/Dispatcher/ComponentDispatcher.php(143): Akeeba\Component\Engage\Administrator\Controller\CommentController->execute('save')
#7 /mnt/data/vhosts/casite-1457196.cloudaccess.net/httpdocs/administrator/components/com_engage/src/Dispatcher/Dispatcher.php(75): Joomla\CMS\Dispatcher\ComponentDispatcher->dispatch()
#8 /mnt/data/vhosts/casite-1457196.cloudaccess.net/httpdocs/libraries/src/Component/ComponentHelper.php(361): Akeeba\Component\Engage\Administrator\Dispatcher\Dispatcher->dispatch()
#9 /mnt/data/vhosts/casite-1457196.cloudaccess.net/httpdocs/libraries/src/Application/SiteApplication.php(218): Joomla\CMS\Component\ComponentHelper::renderComponent('com_engage')
#10 /mnt/data/vhosts/casite-1457196.cloudaccess.net/httpdocs/libraries/src/Application/SiteApplication.php(261): Joomla\CMS\Application\SiteApplication->dispatch()
#11 /mnt/data/vhosts/casite-1457196.cloudaccess.net/httpdocs/libraries/src/Application/CMSApplication.php(306): Joomla\CMS\Application\SiteApplication->doExecute()
#12 /mnt/data/vhosts/casite-1457196.cloudaccess.net/httpdocs/includes/app.php(58): Joomla\CMS\Application\CMSApplication->execute()
#13 /mnt/data/vhosts/casite-1457196.cloudaccess.net/httpdocs/index.php(32): require_once('/mnt/data/vhost...')
#14 {main}

[nikosdion]

You have your answer. The problem is in the Joomla! core itself. I believe this is a regression (a bug introduced lately).