Joomla CLI & console changes: Joomla 3 → 4, 5 and 6

5 issues in this guide

CLI entry points changed shape when application classes became abstract. This guide groups 5 entries: class MyCli extends JApplicationCli, JApplicationCli, JApplicationDaemon, JCli, JDaemon. In Joomla 4+ you extend CliApplication (or the daemon application) and implement protected doExecute() — custom execute() methods you invented on J3 are not the contract. Import Joomla\CMS\Application\CliApplication (or DaemonApplication) and drop JCli / JDaemon globals. Pair CLI work with the Input guide's JInputCli entry if you still read argv through the old input class. Hop mix: 1 at Joomla 3 → 4; 4 at Joomla 5 → 6. Because these are aliases until native Joomla 6, a cron script can look fine on Joomla 5 with the BC plugin and fatal the night you turn the plugin off. Run every CLI script once on staging with Behaviour – Backward Compatibility disabled before the Joomla 6 cutover, using the before/after blocks below. Catalog replacements in this guide include class MyCli extends JApplicationCli → CliApplication + doExecute(); JApplicationCli → Joomla\CMS\Application\CliApplication; JApplicationDaemon → Joomla\CMS\Application\DaemonApplication; JCli → Joomla\CMS\Application\CliApplication. Open each h2 anchor for the full before/after, fix list, and error strings shipped in the reference data.

APP-CLI-DOEXECUTE-001

class MyCli extends JApplicationCli

JApplicationCli is abstract — implement doExecute()

CliApplication (and WebApplication) are abstract in Joomla 4+. The entry point is doExecute(), not a custom execute() you invent.

class MyCli extends JApplicationCli → CliApplication + doExecute()

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

  • Cannot instantiate abstract class
  • Class ... contains 1 abstract method and must therefore be declared abstract

Symptoms people search

CLI script abstract class · doExecute

Replace this code

Swap class MyCli extends JApplicationCli for CliApplication + doExecute().

Joomla 3

Remove or stop calling this

class LmsCli extends JApplicationCli {
    public function execute() { /* old */ }
}

Joomla 4 / 6

Use this instead

class LmsCli extends \Joomla\CMS\Application\CliApplication {
    protected function doExecute(): void { /* your CLI work */ }
}

How to fix it

  1. 1Implement protected doExecute().
  2. 2Do not instantiate CliApplication directly.

Also known as

doExecute · CliApplication abstract · JApplicationWeb abstract

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JAPPLICATIONCLI-CLASS-001

JApplicationCli

JApplicationCli class name

JApplicationCli 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 "JApplicationCli" not found.

JApplicationCli → Joomla\CMS\Application\CliApplication

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 "JApplicationCli" not found
  • Class 'JApplicationCli' not found
  • Failed to open stream: JApplicationCli

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 JApplicationCli for Joomla\CMS\Application\CliApplication.

Joomla 3

Remove or stop calling this

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

Joomla 4 / 6

Use this instead

use Joomla\CMS\Application\CliApplication;

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

How to fix it

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

Also known as

JApplicationCli · Joomla\CMS\Application\CliApplication · class alias · J prefix · JCli

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JAPPLICATIONDAEMON-CLASS-001

JApplicationDaemon

JApplicationDaemon class name

JApplicationDaemon 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 "JApplicationDaemon" not found.

JApplicationDaemon → Joomla\CMS\Application\DaemonApplication

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 "JApplicationDaemon" not found
  • Class 'JApplicationDaemon' not found
  • Failed to open stream: JApplicationDaemon

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 JApplicationDaemon for Joomla\CMS\Application\DaemonApplication.

Joomla 3

Remove or stop calling this

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

Joomla 4 / 6

Use this instead

use Joomla\CMS\Application\DaemonApplication;

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

How to fix it

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

Also known as

JApplicationDaemon · Joomla\CMS\Application\DaemonApplication · class alias · J prefix · JDaemon

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JCLI-CLASS-001

JCli

JCli class name

JCli 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 "JCli" not found.

JCli → Joomla\CMS\Application\CliApplication

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 "JCli" not found
  • Class 'JCli' not found
  • Failed to open stream: JCli

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 JCli for Joomla\CMS\Application\CliApplication.

Joomla 3

Remove or stop calling this

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

Joomla 4 / 6

Use this instead

use Joomla\CMS\Application\CliApplication;

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

How to fix it

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

Also known as

JCli · Joomla\CMS\Application\CliApplication · class alias · J prefix

Scan a ZIP for thisAsk Infyways to fix it

JDAEMON-CLASS-001

JDaemon

JDaemon class name

JDaemon 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 "JDaemon" not found.

JDaemon → Joomla\CMS\Application\DaemonApplication

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 "JDaemon" not found
  • Class 'JDaemon' not found
  • Failed to open stream: JDaemon

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 JDaemon for Joomla\CMS\Application\DaemonApplication.

Joomla 3

Remove or stop calling this

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

Joomla 4 / 6

Use this instead

use Joomla\CMS\Application\DaemonApplication;

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

How to fix it

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

Also known as

JDaemon · Joomla\CMS\Application\DaemonApplication · class alias · J prefix

Scan a ZIP for thisAsk Infyways to fix it

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