What are the common reasons for the extension not being loaded after restarting the Apache server?

The common reasons for an extension not being loaded after restarting the Apache server include incorrect configuration settings in the php.ini file, missing or incorrect extension directory paths, or the extension not being properly installed. To solve this issue, check the php.ini file for any errors, ensure the extension directory path is correct, and reinstall the extension if necessary.

extension=example.so
extension_dir=/path/to/extensions