Fixing PHP Startup Error: Unable to load dynamic library

PHP is a widely-used scripting language that is especially suited for web development. It is fast, flexible, and pragmatic. However, like any other software, it can sometimes throw errors that may seem daunting to fix. One such error is the PHP startup error: “Unable to load dynamic library”. This error often occurs when the PHP configuration file is referencing a Windows-specific extension file on a Linux system. In this article, we will walk you through the steps to resolve this issue.

Understanding the Error

Before we delve into the solution, it’s important to understand the error itself. The full error message usually reads something like this:

PHP Warning: PHP Startup: Unable to load dynamic library '/usr/lib/php/20151012/php_mbstring.dll'

This error message is indicating that PHP is trying to load a dynamic library, specifically ‘php_mbstring.dll’, which it cannot find. The ‘php_mbstring.dll’ is a Windows-specific PHP extension file, and hence, cannot be loaded on a Linux system.

Locating the PHP Configuration File

The first step in resolving this error is to locate and open the PHP configuration file, also known as the php.ini file. This file controls many aspects of PHP’s behavior. In most systems, you can find this file in the ‘/etc/php/7.2/cli/’ directory, but the location can vary depending on your PHP installation.

To open this file, you can use a command-line text editor like nano. The command would be:

sudo nano /etc/php/7.2/cli/php.ini

In this command, sudo is used to execute the command with root privileges, nano is the text editor, and /etc/php/7.2/cli/php.ini is the path to the PHP configuration file.

Checking the PHP Configuration File

Once you have the php.ini file open, look for a line that includes “extension=php_mbstring.dll” or something similar. If you find such a line, this is likely what’s causing the error.

Installing the Correct Package

The next step is to install the correct package for the mbstring extension. If you are using Ubuntu, you can do this by running the following command:

sudo apt-get install php-mbstring

In this command, sudo again gives us root privileges, apt-get is the package handling utility in Ubuntu, install is the command to install a package, and php-mbstring is the package we want to install.

This package will enable the mbstring extension automatically.

Disabling and Enabling the Extension

Sometimes, you may need to manually disable and then enable the mbstring extension. You can do this using the following commands:

To disable the mbstring extension:

sudo phpdismod mbstring

To enable the mbstring extension:

sudo phpenmod mbstring

In these commands, sudo gives us root privileges, phpdismod and phpenmod are utilities to disable and enable PHP extensions, and mbstring is the extension we want to disable or enable.

Conclusion

The PHP startup error “Unable to load dynamic library” can seem intimidating, but it’s usually quite straightforward to fix. By checking the PHP configuration file, installing the correct package, and enabling the extension properly, you should be able to resolve this error and get your PHP installation working smoothly again.

Remember, the specific PHP configuration file location and the correct package to install may vary depending on your system setup. Always make sure to reference the correct extension file in your PHP configuration file.

If you need further assistance, consider checking out the official PHP documentation or the Ubuntu community help pages.