Fixing the "Vendor Autoload is Not Found" Error in Magento 2

The "Vendor Autoload is not found" error in Magento 2 occurs when the platform cannot locate required autoload files in the vendor directory. This directory is crucial because it stores Magento's third-party components and dependencies. Without these files, Magento cannot function correctly.

Common Causes

• Incomplete Installation: This error often appears after a failed or incomplete installation where composer install was not properly executed.
• Missing Files: The vendor folder or its contents may be missing due to manual deletion or corrupted downloads.
• Conflict Between Manual and Composer Installations: If modules are installed using both methods (manual placement in app/code and Composer), duplicate entries can lead to autoload errors【9】【10】.

Steps to Resolve

• Run Composer Install:

Navigate to Magento's root directory and execute:

composer install

Ensure the necessary dependencies are downloaded and properly set up.

• Verify composer.json and composer.lock:

Run composer update to sync dependencies.

• Rebuild Magento:

Run the following commands to refresh the system:

php bin/magento setup:upgrade

php bin/magento setup:di:compile

php bin/magento cache:flush

• Resolve Duplicates:

Remove manually installed modules (app/code) if they're also installed via Composer. Keep one version to avoid conflicts.

• Restore Missing Files:

If the vendor directory is missing, restore it by running composer install again.

Causes of the "Vendor Autoload Not Found" Error

The "Vendor Autoload Not Found" error in Magento often arises due to issues with the Composer setup or file access. Here's a breakdown of the main causes and potential fixes:

Common Causes:

• Incomplete Composer Installation

The installation process might have been interrupted or improperly completed, leaving critical files missing.

• File Permission Issues

If Magento lacks sufficient permissions to access the vendor directory, it cannot load the necessary files. Misconfigured file access is a common root cause.

• Corrupted or Missing Composer Cache

A corrupted cache can disrupt dependency installation and file creation, leading to the error.

• Incorrect Command Usage

Running Magento or Composer commands without the required privileges can result in incomplete execution.

Resolving the "Magento 2 Vendor Autoload is Not Found" Error

Facing the "Vendor Autoload is Not Found" error in Magento 2 can be frustrating, especially during installation or while setting up a local instance. This guide walks you through fixing it effectively.

Step-by-Step Solution

To increase the memory limit, follow these steps:

• Run the PHP Command with Increased Memory:

Use the following commands, replacing 1G with the amount of memory you want to allocate:

php -d memory_limit=1G bin/magento setup:di:compile

php -d memory_limit=1G bin/magento setup:static-content:deploy

• Adjust php.iniConfiguration:

If the above doesn't resolve the issue, update the php.ini file:

memory_limit = 2G

Alternative for Servers Without Shell Access

If your server doesn't allow running composer install (e.g., shared hosting), you can use the following workaround:

• Run composer install on a local machine where you have full access.
• Copy the generated vendor folder to your server along with the rest of your Magento files.

This method ensures that all required dependencies are properly configured, even without direct server access.