How many Router & SEF issues are in this guide?

This guide covers 16 catalog entries with before/after replacements.

Joomla Router & SEF changes: Joomla 3 → 4, 5 and 6

16 issues in this guide

Routing and SEF break when extension routers still assume Joomla 3 includes and JRoute/JUri globals. This guide groups 16 entries: JApplicationWebRouterRest, JComponentRouterLegacy, JFactory::getUri(), JHelperRoute, class MyMenu extends JMenu, JMenu, JMenuItem, $item->params->get('show_title'), JPathway, JRoute, and 6 more. The replacement pattern is Route::_() / Uri::getInstance() from the CMS Router and Uri namespaces, menu params via getParams()/setParams(), and component routers built on RouterView + rules instead of legacy JComponentRouterLegacy subclasses or require JPATH_SITE.'/includes/router.php'. REST-style JApplicationWebRouter* classes are gone — rebuild on Joomla Web Services or the joomla/router package. Hop mix: 6 at Joomla 3 → 4; 10 at Joomla 5 → 6. Run a staging pass with SEF on and off so you catch both alias removals (J5→J6) and structural removals (J3→J4). Each entry below shows the concrete class or call to delete and what the catalog lists as the replacement. Catalog replacements in this guide include JApplicationWebRouterRest → joomla/router package; JComponentRouterLegacy → Joomla\CMS\Component\Router\RouterBase; JFactory::getUri() → Uri::getInstance(); JHelperRoute → Joomla\CMS\Helper\RouteHelper. Open each h2 anchor for the full before/after, fix list, and error strings shipped in the reference data.

JAPP-WEB-ROUTER-001

JApplicationWebRouterRest

JApplicationWebRouter*

The old web-app REST router classes were removed.

JApplicationWebRouterRest → joomla/router package

Dies at Joomla 3 → 4

Dies at Joomla 3 → 4J3: Works nativelyJ4: Removed — fatalJ6: Removed — fatalBC plugin: no — already dead on J4Architecture change — no auto-fixJoomla API

What you will see

Class "JApplicationWebRouter" not found
Class "JApplicationWebRouterRest" not found

Symptoms people search

custom REST router fatal

Replace this code

Swap JApplicationWebRouterRest for joomla/router package.

Joomla 3

Remove or stop calling this

$router = new JApplicationWebRouterRest($app);

Joomla 4 / 6

Use this instead

Use Joomla\Router\Router from the router package / component RouterView.

How to fix it

1Rebuild API routing on Joomla Web Services or joomla/router.

Also known as

JApplicationWebRouterBase · JApplicationWebRouterRest

There is no 1:1 swap for this one. The architecture changed. If you cannot rewrite it, Infyways can.

Scan a ZIP for this Ask Infyways to fix it

JCOMPONENTROUTER-CLASS-001

JComponentRouterLegacy

JComponentRouterLegacy class name

JComponentRouterLegacy is a Joomla 3 global class. Joomla 4 still has an alias. Joomla 5 needs the Behaviour – Backward Compatibility plugin. Native Joomla 6 does not load that alias — you get Class "JComponentRouterLegacy" not found.

JComponentRouterLegacy → Joomla\CMS\Component\Router\RouterBase

Dies at Joomla 5 → 6

Dies at Joomla 5 → 6J3: Works nativelyJ4: Alias (old name still resolves)J6: Removed — fatalBC plugin: covers the class nameMechanical renameJoomla API

What you will see

Class "JComponentRouterLegacy" not found
Class 'JComponentRouterLegacy' not found
Failed to open stream: JComponentRouterLegacy

Symptoms people search

white screen after disabling compatibility plugin · class not found on Joomla 6 · works on Joomla 5 until I turn off backward compatibility

Replace this code

Swap JComponentRouterLegacy for Joomla\CMS\Component\Router\RouterBase.

Joomla 3

Remove or stop calling this

JComponentRouterLegacy::getInstance();
// or new JComponentRouterLegacy()

Joomla 4 / 6

Use this instead

use Joomla\CMS\Component\Router\RouterBase;

// Call the namespaced class. Do not keep the J prefix.

How to fix it

1Add a use statement for Joomla\CMS\Component\Router\RouterBase.
2Replace every JComponentRouterLegacy with the short class name from that use line.
3Disable Behaviour – Backward Compatibility on a Joomla 5 staging site. If it fatals, this class is still in the code.

Also known as

JComponentRouterLegacy · Joomla\CMS\Component\Router\RouterBase · class alias · J prefix

Scan a ZIP for this Ask Infyways to fix it

JFACTORY-GETURI-001

JFactory::getUri()

Factory::getUri()

getUri() was removed from Factory in Joomla 4. Use the Uri class.

JFactory::getUri() → Uri::getInstance()

Dies at Joomla 3 → 4

Dies at Joomla 3 → 4J3: Works nativelyJ4: Removed — fatalJ6: Removed — fatalBC plugin: no — already dead on J4Mechanical renameJoomla API

What you will see

Call to undefined method Joomla\CMS\Factory::getUri
Call to undefined method JFactory::getURI

Symptoms people search

canonical URL code fatals

Replace this code

Swap JFactory::getUri() for Uri::getInstance().

Joomla 3

Remove or stop calling this

$uri = JFactory::getURI();
echo $uri->toString();

Joomla 4 / 6

Use this instead

use Joomla\CMS\Uri\Uri;

$uri = Uri::getInstance();

How to fix it

1Replace Factory::getUri()/getURI() with Uri::getInstance().

Also known as

JFactory::getUri()

Scan a ZIP for this Ask Infyways to fix it

JHELPERROUTE-CLASS-001

JHelperRoute

JHelperRoute class name

JHelperRoute is a Joomla 3 global class. Joomla 4 still has an alias. Joomla 5 needs the Behaviour – Backward Compatibility plugin. Native Joomla 6 does not load that alias — you get Class "JHelperRoute" not found.

JHelperRoute → Joomla\CMS\Helper\RouteHelper

Dies at Joomla 5 → 6

Dies at Joomla 5 → 6J3: Works nativelyJ4: Alias (old name still resolves)J6: Removed — fatalBC plugin: covers the class nameMechanical renameJoomla API

What you will see

Class "JHelperRoute" not found
Class 'JHelperRoute' not found
Failed to open stream: JHelperRoute

Symptoms people search

white screen after disabling compatibility plugin · class not found on Joomla 6 · works on Joomla 5 until I turn off backward compatibility

Replace this code

Swap JHelperRoute for Joomla\CMS\Helper\RouteHelper.

Joomla 3

Remove or stop calling this

JHelperRoute::getInstance();
// or new JHelperRoute()

Joomla 4 / 6

Use this instead

use Joomla\CMS\Helper\RouteHelper;

// Call the namespaced class. Do not keep the J prefix.

How to fix it

1Add a use statement for Joomla\CMS\Helper\RouteHelper.
2Replace every JHelperRoute with the short class name from that use line.
3Disable Behaviour – Backward Compatibility on a Joomla 5 staging site. If it fatals, this class is still in the code.

Also known as

JHelperRoute · Joomla\CMS\Helper\RouteHelper · class alias · J prefix

Scan a ZIP for this Ask Infyways to fix it

JMENU-ABSTRACT-001

class MyMenu extends JMenu

JMenu is abstract — you must implement load()

JMenu became AbstractMenu. Subclasses that do not implement load() are abstract and fatal.

class MyMenu extends JMenu → Extend AbstractMenu and implement load()

Dies at Joomla 3 → 4

Dies at Joomla 3 → 4J3: Works nativelyJ4: Changed behaviourJ6: Removed — fatalBC plugin: partialPatch possible — review itJoomla API

What you will see

Class LmsMenu contains 1 abstract method
Cannot instantiate abstract class

Symptoms people search

menu class abstract · JMenu load()

Replace this code

Swap class MyMenu extends JMenu for Extend AbstractMenu and implement load().

Joomla 3

Remove or stop calling this

class LmsMenu extends JMenu {
    // Joomla 3 allowed incomplete subclasses
}

Joomla 4 / 6

Use this instead

class LmsMenu extends \Joomla\CMS\Menu\AbstractMenu {
    public function load() { /* return items */ return true; }
}

How to fix it

1Implement load().
2Use the namespaced AbstractMenu.

Also known as

AbstractMenu · JMenu load · doExecute

Scan a ZIP for this Ask Infyways to fix it

JMENU-CLASS-001

JMenu

JMenu class name

JMenu is a Joomla 3 global class. Joomla 4 still has an alias. Joomla 5 needs the Behaviour – Backward Compatibility plugin. Native Joomla 6 does not load that alias — you get Class "JMenu" not found.

JMenu → Joomla\CMS\Menu\AbstractMenu

Dies at Joomla 5 → 6

Dies at Joomla 5 → 6J3: Works nativelyJ4: Alias (old name still resolves)J6: Removed — fatalBC plugin: covers the class nameMechanical renameJoomla API

What you will see

Class "JMenu" not found
Class 'JMenu' not found
Failed to open stream: JMenu

Symptoms people search

white screen after disabling compatibility plugin · class not found on Joomla 6 · works on Joomla 5 until I turn off backward compatibility

Replace this code

Swap JMenu for Joomla\CMS\Menu\AbstractMenu.

Joomla 3

Remove or stop calling this

JMenu::getInstance();
// or new JMenu()

Joomla 4 / 6

Use this instead

use Joomla\CMS\Menu\AbstractMenu;

// Call the namespaced class. Do not keep the J prefix.

How to fix it

1Add a use statement for Joomla\CMS\Menu\AbstractMenu.
2Replace every JMenu with the short class name from that use line.
3Disable Behaviour – Backward Compatibility on a Joomla 5 staging site. If it fatals, this class is still in the code.

Also known as

JMenu · Joomla\CMS\Menu\AbstractMenu · class alias · J prefix

Scan a ZIP for this Ask Infyways to fix it

JMENUITEM-CLASS-001

JMenuItem

JMenuItem class name

JMenuItem is a Joomla 3 global class. Joomla 4 still has an alias. Joomla 5 needs the Behaviour – Backward Compatibility plugin. Native Joomla 6 does not load that alias — you get Class "JMenuItem" not found.

JMenuItem → Joomla\CMS\Menu\MenuItem

Dies at Joomla 5 → 6

Dies at Joomla 5 → 6J3: Works nativelyJ4: Alias (old name still resolves)J6: Removed — fatalBC plugin: covers the class nameMechanical renameJoomla API

What you will see

Class "JMenuItem" not found
Class 'JMenuItem' not found
Failed to open stream: JMenuItem

Symptoms people search

white screen after disabling compatibility plugin · class not found on Joomla 6 · works on Joomla 5 until I turn off backward compatibility

Replace this code

Swap JMenuItem for Joomla\CMS\Menu\MenuItem.

Joomla 3

Remove or stop calling this

JMenuItem::getInstance();
// or new JMenuItem()

Joomla 4 / 6

Use this instead

use Joomla\CMS\Menu\MenuItem;

// Call the namespaced class. Do not keep the J prefix.

How to fix it

1Add a use statement for Joomla\CMS\Menu\MenuItem.
2Replace every JMenuItem with the short class name from that use line.
3Disable Behaviour – Backward Compatibility on a Joomla 5 staging site. If it fatals, this class is still in the code.

Also known as

JMenuItem · Joomla\CMS\Menu\MenuItem · class alias · J prefix

Scan a ZIP for this Ask Infyways to fix it

JMENUITEM-PARAMS-001

$item->params->get('show_title')

JMenuItem public $params

Menu item params are no longer a public Registry property in Joomla 4.

$item->params->get('show_title') → getParams() / setParams()

Dies at Joomla 3 → 4

Dies at Joomla 3 → 4J3: Works nativelyJ4: Removed — fatalJ6: Removed — fatalBC plugin: no — already dead on J4Mechanical renameJoomla API

What you will see

Attempt to read property "params" on
Undefined property: MenuItem::$params

Symptoms people search

menu item params empty · item->params

Replace this code

Swap $item->params->get('show_title') for getParams() / setParams().

Joomla 3

Remove or stop calling this

$show = $item->params->get('show_title');

Joomla 4 / 6

Use this instead

$show = $item->getParams()->get('show_title');

How to fix it

1Use getParams().

Also known as

MenuItem params · getParams

Scan a ZIP for this Ask Infyways to fix it

JPATHWAY-CLASS-001

JPathway

JPathway class name

JPathway is a Joomla 3 global class. Joomla 4 still has an alias. Joomla 5 needs the Behaviour – Backward Compatibility plugin. Native Joomla 6 does not load that alias — you get Class "JPathway" not found.

JPathway → Joomla\CMS\Pathway\Pathway

Dies at Joomla 5 → 6

Dies at Joomla 5 → 6J3: Works nativelyJ4: Alias (old name still resolves)J6: Removed — fatalBC plugin: covers the class nameMechanical renameJoomla API

What you will see

Class "JPathway" not found
Class 'JPathway' not found
Failed to open stream: JPathway

Symptoms people search

white screen after disabling compatibility plugin · class not found on Joomla 6 · works on Joomla 5 until I turn off backward compatibility

Replace this code

Swap JPathway for Joomla\CMS\Pathway\Pathway.

Joomla 3

Remove or stop calling this

JPathway::getInstance();
// or new JPathway()

Joomla 4 / 6

Use this instead

use Joomla\CMS\Pathway\Pathway;

// Call the namespaced class. Do not keep the J prefix.

How to fix it

1Add a use statement for Joomla\CMS\Pathway\Pathway.
2Replace every JPathway with the short class name from that use line.
3Disable Behaviour – Backward Compatibility on a Joomla 5 staging site. If it fatals, this class is still in the code.

Also known as

JPathway · Joomla\CMS\Pathway\Pathway · class alias · J prefix

Scan a ZIP for this Ask Infyways to fix it

JROUTE-CLASS-001

JRoute

JRoute class name

JRoute is a Joomla 3 global class. Joomla 4 still has an alias. Joomla 5 needs the Behaviour – Backward Compatibility plugin. Native Joomla 6 does not load that alias — you get Class "JRoute" not found.

JRoute → Joomla\CMS\Router\Route

Dies at Joomla 5 → 6

Dies at Joomla 5 → 6J3: Works nativelyJ4: Alias (old name still resolves)J6: Removed — fatalBC plugin: covers the class nameMechanical renameJoomla API

What you will see

Class "JRoute" not found
Class 'JRoute' not found
Failed to open stream: JRoute

Symptoms people search

white screen after disabling compatibility plugin · class not found on Joomla 6 · works on Joomla 5 until I turn off backward compatibility

Replace this code

Swap JRoute for Joomla\CMS\Router\Route.

Joomla 3

Remove or stop calling this

JRoute::getInstance();
// or new JRoute()

Joomla 4 / 6

Use this instead

use Joomla\CMS\Router\Route;

// Call the namespaced class. Do not keep the J prefix.

How to fix it

1Add a use statement for Joomla\CMS\Router\Route.
2Replace every JRoute with the short class name from that use line.
3Disable Behaviour – Backward Compatibility on a Joomla 5 staging site. If it fatals, this class is still in the code.

Also known as

JRoute · Joomla\CMS\Router\Route · class alias · J prefix

Scan a ZIP for this Ask Infyways to fix it

JROUTER-CLASS-001

JRouter

JRouter class name

JRouter is a Joomla 3 global class. Joomla 4 still has an alias. Joomla 5 needs the Behaviour – Backward Compatibility plugin. Native Joomla 6 does not load that alias — you get Class "JRouter" not found.

JRouter → Joomla\CMS\Router\Router

Dies at Joomla 5 → 6

Dies at Joomla 5 → 6J3: Works nativelyJ4: Alias (old name still resolves)J6: Removed — fatalBC plugin: covers the class nameMechanical renameJoomla API

What you will see

Class "JRouter" not found
Class 'JRouter' not found
Failed to open stream: JRouter

Symptoms people search

white screen after disabling compatibility plugin · class not found on Joomla 6 · works on Joomla 5 until I turn off backward compatibility

Replace this code

Swap JRouter for Joomla\CMS\Router\Router.

Joomla 3

Remove or stop calling this

JRouter::getInstance();
// or new JRouter()

Joomla 4 / 6

Use this instead

use Joomla\CMS\Router\Router;

// Call the namespaced class. Do not keep the J prefix.

How to fix it

1Add a use statement for Joomla\CMS\Router\Router.
2Replace every JRouter with the short class name from that use line.
3Disable Behaviour – Backward Compatibility on a Joomla 5 staging site. If it fatals, this class is still in the code.

Also known as

JRouter · Joomla\CMS\Router\Router · class alias · J prefix

Scan a ZIP for this Ask Infyways to fix it

JROUTER-GETINSTANCE-001

require JPATH_SITE . '/includes/router.php'

JRouter::getInstance() + includes/router.php

Manually including includes/router.php is gone. The router is on the application.

require JPATH_SITE . '/includes/router.php' → Autoloaded Router class

Dies at Joomla 3 → 4

Dies at Joomla 3 → 4J3: Works nativelyJ4: Removed — fatalJ6: Removed — fatalBC plugin: no — already dead on J4Patch possible — review itJoomla API

What you will see

Failed opening required 'includes/router.php'
Call to undefined method JRouter::getInstance

Symptoms people search

SEF router include fatal

Replace this code

Swap require JPATH_SITE . '/includes/router.php' for Autoloaded Router class.

Joomla 3

Remove or stop calling this

require_once JPATH_SITE . '/includes/router.php';
$router = JRouter::getInstance('site');

Joomla 4 / 6

Use this instead

$router = Factory::getApplication()->getRouter();

How to fix it

1Delete the require.
2Use $app->getRouter().

Also known as

includes/router.php · JRouter::getInstance

Scan a ZIP for this Ask Infyways to fix it

JROUTERADMIN-CLASS-001

JRouterAdministrator

JRouterAdministrator class name

JRouterAdministrator is a Joomla 3 global class. Joomla 4 still has an alias. Joomla 5 needs the Behaviour – Backward Compatibility plugin. Native Joomla 6 does not load that alias — you get Class "JRouterAdministrator" not found.

JRouterAdministrator → Joomla\CMS\Router\AdministratorRouter

Dies at Joomla 5 → 6

Dies at Joomla 5 → 6J3: Works nativelyJ4: Alias (old name still resolves)J6: Removed — fatalBC plugin: covers the class nameMechanical renameJoomla API

What you will see

Class "JRouterAdministrator" not found
Class 'JRouterAdministrator' not found
Failed to open stream: JRouterAdministrator

Symptoms people search

white screen after disabling compatibility plugin · class not found on Joomla 6 · works on Joomla 5 until I turn off backward compatibility

Replace this code

Swap JRouterAdministrator for Joomla\CMS\Router\AdministratorRouter.

Joomla 3

Remove or stop calling this

JRouterAdministrator::getInstance();
// or new JRouterAdministrator()

Joomla 4 / 6

Use this instead

use Joomla\CMS\Router\AdministratorRouter;

// Call the namespaced class. Do not keep the J prefix.

How to fix it

1Add a use statement for Joomla\CMS\Router\AdministratorRouter.
2Replace every JRouterAdministrator with the short class name from that use line.
3Disable Behaviour – Backward Compatibility on a Joomla 5 staging site. If it fatals, this class is still in the code.

Also known as

JRouterAdministrator · Joomla\CMS\Router\AdministratorRouter · class alias · J prefix

Scan a ZIP for this Ask Infyways to fix it

JROUTERSITE-CLASS-001

JRouterSite

JRouterSite class name

JRouterSite is a Joomla 3 global class. Joomla 4 still has an alias. Joomla 5 needs the Behaviour – Backward Compatibility plugin. Native Joomla 6 does not load that alias — you get Class "JRouterSite" not found.

JRouterSite → Joomla\CMS\Router\SiteRouter

Dies at Joomla 5 → 6

Dies at Joomla 5 → 6J3: Works nativelyJ4: Alias (old name still resolves)J6: Removed — fatalBC plugin: covers the class nameMechanical renameJoomla API

What you will see

Class "JRouterSite" not found
Class 'JRouterSite' not found
Failed to open stream: JRouterSite

Symptoms people search

white screen after disabling compatibility plugin · class not found on Joomla 6 · works on Joomla 5 until I turn off backward compatibility

Replace this code

Swap JRouterSite for Joomla\CMS\Router\SiteRouter.

Joomla 3

Remove or stop calling this

JRouterSite::getInstance();
// or new JRouterSite()

Joomla 4 / 6

Use this instead

use Joomla\CMS\Router\SiteRouter;

// Call the namespaced class. Do not keep the J prefix.

How to fix it

1Add a use statement for Joomla\CMS\Router\SiteRouter.
2Replace every JRouterSite with the short class name from that use line.
3Disable Behaviour – Backward Compatibility on a Joomla 5 staging site. If it fatals, this class is still in the code.

Also known as

JRouterSite · Joomla\CMS\Router\SiteRouter · class alias · J prefix

Scan a ZIP for this Ask Infyways to fix it

JURI-CLASS-001

JUri

JUri class name

JUri is a Joomla 3 global class. Joomla 4 still has an alias. Joomla 5 needs the Behaviour – Backward Compatibility plugin. Native Joomla 6 does not load that alias — you get Class "JUri" not found.

JUri → Joomla\CMS\Uri\Uri

Dies at Joomla 5 → 6

Dies at Joomla 5 → 6J3: Works nativelyJ4: Alias (old name still resolves)J6: Removed — fatalBC plugin: covers the class nameMechanical renameJoomla API

What you will see

Class "JUri" not found
Class 'JUri' not found
Failed to open stream: JUri

Symptoms people search

white screen after disabling compatibility plugin · class not found on Joomla 6 · works on Joomla 5 until I turn off backward compatibility

Replace this code

Swap JUri for Joomla\CMS\Uri\Uri.

Joomla 3

Remove or stop calling this

JUri::getInstance();
// or new JUri()

Joomla 4 / 6

Use this instead

use Joomla\CMS\Uri\Uri;

// Call the namespaced class. Do not keep the J prefix.

How to fix it

1Add a use statement for Joomla\CMS\Uri\Uri.
2Replace every JUri with the short class name from that use line.
3Disable Behaviour – Backward Compatibility on a Joomla 5 staging site. If it fatals, this class is still in the code.

Also known as

JUri · Joomla\CMS\Uri\Uri · class alias · J prefix

Scan a ZIP for this Ask Infyways to fix it

SEF-ROUTER-001

Joomla 3 router + system SEF plugin hacks

index.php?option= SEF assumptions / plg_system_sef

Joomla 4 rebuilt SEF. Plugins that rewrite query strings the J3 way break menus, multilingual, and API routes.

Joomla 3 router + system SEF plugin hacks → Component RouterView + rules

Dies at Joomla 3 → 4

Dies at Joomla 3 → 4J3: Works nativelyJ4: Changed behaviourJ6: Changed behaviourBC plugin: not applicableArchitecture change — no auto-fixJoomla API

Symptoms people search

404 after upgrade · SEF urls broken · index.php? still showing

Replace this code

Swap Joomla 3 router + system SEF plugin hacks for Component RouterView + rules.

Joomla 3

Remove or stop calling this

// Parse $_SERVER['REQUEST_URI'] by exploding index.php?option=com_lms&view=course&id=

Joomla 4 / 6

Use this instead

Implement RouterView / RouterViewConfiguration for com_lms. Do not str_replace on index.php? in a system plugin.

How to fix it

1Write a component router.
2Retest menu items and language associations.

Also known as

plg_system_sef · RouterView · SEF 404

There is no 1:1 swap for this one. The architecture changed. If you cannot rewrite it, Infyways can.

Scan a ZIP for this Ask Infyways to fix it