What potential pitfalls should be considered when converting file extensions from .htm to .php in PHP?

When converting file extensions from .htm to .php in PHP, potential pitfalls to consider include ensuring that all links and references within the files are updated to reflect the new extension, handling any server configuration changes that may be necessary to process PHP files, and ensuring that any existing HTML code does not conflict with PHP code.

// Example PHP code snippet to handle conversion of file extensions from .htm to .php

// Update all links and references within the files to reflect the new extension
// This can be done manually or using a script to search and replace the file contents

// Make sure that the server is configured to process PHP files
// This may involve updating the server configuration or adding a handler for PHP files

// Check for any conflicts between existing HTML code and PHP code
// Ensure that PHP code is properly enclosed within <?php ?> tags and does not interfere with existing HTML