How to Fix “Uncaught Error: Class ‘Magento\Setup\Mvc\Bootstrap\InitParamListener’ not found” Error After Upgrading to Magento 2.4.x?

Upgrading the Magento platform is always recommended. But sometimes, updating the platform comes with errors.

In this quick tutorial, we will be looking at how to fix “Uncaught Error: Class ‘Magento\Setup\Mvc\Bootstrap\InitParamListener’ not found” Error After Upgrading to Magento 2.4.x?

After upgrading the Magento store to the version 2.4.x, when you try to run the Magento setup upgrade command, it can show an error like:

PHP Fatal Error: “Uncaught Error: Class ‘Magento\Setup\Mvc\Bootstrap\InitParamListener’ not found”

How to Fix Class ‘Magento\Setup\Mvc\Bootstrap\InitParamListener’ not found Error in Magento 2?

Follow the steps to fix the error:

Step 1: Navigate to the Magento root directory

Step 2: Run the following command from the terminal

rm -rf vendor

The command will delete the contents of the vendor.

Read: Command Magento CLI Commands

Step 3: Install the composer by running the following command on the Magento root directory from the terminal.

composer install

Wrap Up

The first command deletes the vendor content. And the second command installs the composer again.

Multiple Magento errors to solve:

• Solve There has been an error processing your request in Magento
• “Error Establishing a Database Connection” – How to Fix it
• Solve Exception printing is disabled by default for security reasons in Magento 2
• Failed to Load API Definition in Magento 2 Swagger

I hope this tutorial helps you to solve the Magento\Setup\Mvc\Bootstrap error. If you find more Magento errors and are not able to solve them, feel free to get in touch.