An error occurred after downgrading from J4 to J3 Topic is solved

[Masterpiece01]

Thanks @Toivo
Installed joomla 3.10.11 php 7.4 my administrator should work but I'm facing serious issues with my admin panel any of the hamburger menu I click shows error.. though the website is working (aifl-institute.com)

Screenshot_20230324-085501_Chrome.jpg

Error

An error has occurred.

0 Call to undefined method Joomla\CMS\Form\Field\PluginsField::getDatabase()
/home2/aiflinstitute/public_html/libraries/src/Form/Field/PluginsField.php:122

Call stack#FunctionLocation1()JROOT/libraries/src/Form/Field/PluginsField.php:1222Joomla\CMS\Form\Field\PluginsField->getOptions()JROOT/libraries/src/Form/Field/ListField.php:633Joomla\CMS\Form\Field\ListField->getInput()JROOT/libraries/src/Form/FormField.php:4254Joomla\CMS\Form\FormField->__get()JROOT/libraries/src/Form/Field/ListField.php:2335Joomla\CMS\Form\Field\ListField->__get()JROOT/libraries/src/Form/Field/PluginsField.php:586Joomla\CMS\Form\Field\PluginsField->__get()JROOT/layouts/joomla/content/options_default.php:337include()JROOT/libraries/src/Layout/FileLayout.php:1258Joomla\CMS\Layout\FileLayout->render()JROOT/libraries/src/Layout/LayoutHelper.php:739Joomla\CMS\Layout\LayoutHelper::render()JROOT/administrator/components/com_config/view/application/tmpl/default_site.php:1410include()JROOT/components/com_config/view/cms/html.php:14211ConfigViewCmsHtml->loadTemplate()JROOT/administrator/components/com_config/view/application/tmpl/default.php:7312include()JROOT/libraries/joomla/view/html.php:15113JViewHtml->render()JROOT/administrator/components/com_config/view/application/html.php:7914ConfigViewApplicationHtml->render()JROOT/components/com_config/controller/display.php:11415ConfigControllerDisplay->execute()JROOT/administrator/components/com_config/config.php:3116require_once()JROOT/libraries/src/Component/ComponentHelper.php:40217Joomla\CMS\Component\ComponentHelper::executeComponent()JROOT/libraries/src/Component/ComponentHelper.php:37718Joomla\CMS\Component\ComponentHelper::renderComponent()JROOT/libraries/src/Application/AdministratorApplication.php:10119Joomla\CMS\Application\AdministratorApplication-

[toivo]

0 Call to undefined method Joomla\CMS\Form\Field\PluginsField::getDatabase()
/home2/aiflinstitute/public_html/libraries/src/Form/Field/PluginsField.php:122

Joomla 3.10.11 does not have a file called PluginsField.php in the folder libraries/src/Form/Field but Joomla 4.2.9 does. It looks like Joomla 3.10.11 was installed into a folder that was not empty.

This topic is now back to where it started with the same error message as before, after Joomla 4 was "downgraded" to Joomla 3.10.

[Masterpiece01]

Yes sir!! I don't what to do at this point please help @Toivo

[toivo]

So the website is now using Joomla 3 and it seems to be working. The login module at the back end displays the following warning, which may explain why the front end is in disarray:

Warning
RokSprocket needs the RokCommon Library and Plug-in installed and enabled. The RokCommon System Plug-in needs to be before the RokSprocket System Plug-in in the Plug-in Manager
RokGallery needs the RokCommon Library and Plug-in installed and enabled. The RokCommon System Plug-in needs to be before the RokGallery System Plug-in in the Plug-in Manager

Install Akeeba Backup and use it. Create a full backup before changes and updates so that you always have a working copy of the website to go back to. If something does wrong, do troubleshooting setting Error Reporting to 'Maximum' ('maximum' if editing the file configuration.php in the main Joomla folder) and turn on the Debug option. Always restore into an empty folder and a new database schema, which avoids merging different versions of Joomla and making the website unworkable.

Go back to be beginning of the topic, read the posts and plan the next steps using a pen and paper. Uninstall extensions that are not compatible before updating to Joomla 4. Stick to the plan and tick the boxes as you go. Install Wampserver or another bundle on a workstation and do a trial update first. Ask the questions in this topic or create a new topic if something totally new comes up.

[Masterpiece01]

Ok thanks so much for your response sir